added configuration over https / http

.env.template

@@ -0,0 +1,29 @@
+# .env.template
+# ============================================
+# DOCKER COMPOSE ENVIRONMENT TEMPLATE
+# Copy this file to .env and adjust values
+# ============================================
+
+# Application settings
+NODE_ENV=production
+JWT_SECRET=your-secret-key-please-change
+HOSTNAME=localhost
+
+# Security & Network
+TRUST_PROXY_ENABLED=false
+TRUSTED_PROXY_IPS=127.0.0.1,::1
+FORCE_HTTPS=false
+
+# Database
+DATABASE_PATH=/app/data/schichtplaner.db
+
+# Optional features
+ENABLE_PRO=false
+DEBUG=false
+
+# Port configuration
+APP_PORT=3002
+
+# ============================================
+# END OF TEMPLATE
+# ============================================

.github/workflows/docker.yml

@@ -16,11 +16,21 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       tag_name: ${{ steps.set_tag.outputs.tag_name }}
+      is_main_branch: ${{ steps.branch_check.outputs.is_main }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
         with:
-          fetch-depth: 0  # Fetch all history for tags
+          fetch-depth: 0
+
+      - name: Check if main branch
+        id: branch_check
+        run: |
+          if [[ "${{ github.ref }}" == "refs/heads/main" || "${{ github.ref }}" == "refs/heads/master" ]]; then
+            echo "is_main=true" >> $GITHUB_OUTPUT
+          else
+            echo "is_main=false" >> $GITHUB_OUTPUT
+          fi
 
       - name: Determine next semantic version tag
         id: set_tag
@@ -29,24 +39,31 @@ jobs:
 
           # Find latest tag matching vX.Y.Z
           latest_tag=$(git tag --list 'v*.*.*' --sort=-v:refname | head -n 1)
+          echo "Latest tag found: $latest_tag"
+          
           if [[ -z "$latest_tag" ]]; then
             major=0
             minor=0
             patch=0
+            echo "No existing tags found, starting from v0.0.0"
           else
             version="${latest_tag#v}"
             IFS='.' read -r major minor patch <<< "$version"
+            echo "Parsed version: major=$major, minor=$minor, patch=$patch"
           fi
 
-          if [[ "${GITHUB_REF}" == "refs/heads/main" || "${GITHUB_REF}" == "refs/heads/master" ]]; then
+          if [[ "${{ github.ref }}" == "refs/heads/main" || "${{ github.ref }}" == "refs/heads/master" ]]; then
             major=$((major + 1))
             minor=0
             patch=0
-          elif [[ "${GITHUB_REF}" == "refs/heads/development" ]]; then
+            echo "Main branch - major version bump"
+          elif [[ "${{ github.ref }}" == "refs/heads/development" ]]; then
             minor=$((minor + 1))
             patch=0
+            echo "Development branch - minor version bump"
           else
             patch=$((patch + 1))
+            echo "Other branch - patch version bump"
           fi
 
           new_tag="v${major}.${minor}.${patch}"
@@ -65,14 +82,10 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: '20'
-          cache: 'npm'
-          cache-dependency-path: backend/package-lock.json
 
       - name: Install backend dependencies
         working-directory: ./backend
-        run: |
-          # Try npm ci first, if it fails use npm install
-          npm ci || (echo "package-lock.json out of sync, using npm install..." && npm install)
+        run: npm install
 
       - name: Run TypeScript check
         working-directory: ./backend
@@ -81,7 +94,6 @@ jobs:
       - name: Run backend tests
         working-directory: ./backend
         run: |
-          # Skip tests if jest is not installed
           if [ -f "node_modules/.bin/jest" ]; then
             npm test
           else
@@ -134,11 +146,8 @@ jobs:
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |
-            type=ref,event=branch
-            type=semver,pattern={{version}}
-            type=sha
-            # Add the dynamically generated semantic version
-            ${{ needs.set-tag.outputs.tag_name }}
+            type=raw,value=${{ needs.set-tag.outputs.tag_name }}
+            type=raw,value=latest,enable=${{ fromJSON(needs.set-tag.outputs.is_main_branch) }}
 
       - name: Build and push Docker image
         uses: docker/build-push-action@v5
@@ -168,3 +177,4 @@ jobs:
           echo "- Image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}"
           echo "- Tags: ${{ steps.meta.outputs.tags }}"
           echo "- New version: ${{ needs.set-tag.outputs.tag_name }}"
+          echo "- Is main branch: ${{ needs.set-tag.outputs.is_main_branch }}"

.gitignore

@@ -64,6 +64,7 @@ build/
 .env.development.local
 .env.test.local
 .env.production.local
+.env.production
 
 # Database
 database/*.db
@@ -110,3 +111,29 @@ Thumbs.db
 
 # Optional eslint cache
 .eslintcache
+
+# Ignore contents of premium folder in public repo
+premium/*
+!premium/README-PREMIUM.md
+!premium/.gitkeep
+
+.git
+.gitignore
+node_modules
+npm-debug.log
+README.md
+.env
+.nyc_output
+coverage
+.cache
+dist
+build
+logs
+*.tsbuildinfo
+
+# Frontend specific
+frontend/dist
+frontend/.vite
+
+# Backend specific  
+backend/dist

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "premium"]
+	path = premium
+	url = https://github.com/donpat1to/Schichtenplaner-Pro.git

Dockerfile

@@ -1,7 +1,7 @@
-# Multi-stage build for combined frontend + backend
-FROM node:20-bullseye AS backend-builder
+# Single stage build for workspaces
+FROM node:20-bullseye AS builder
 
-WORKDIR /app/backend
+WORKDIR /app
 
 # Install Python + OR-Tools
 RUN apt-get update && apt-get install -y python3 python3-pip build-essential \
@@ -10,81 +10,77 @@ RUN apt-get update && apt-get install -y python3 python3-pip build-essential \
 # Create symlink so python3 is callable as python
 RUN ln -sf /usr/bin/python3 /usr/bin/python
 
-# Copy backend files
-COPY backend/package*.json ./
-COPY backend/tsconfig.json ./
+# Copy root package files first
+COPY package*.json ./
+COPY tsconfig.base.json ./
+COPY ecosystem.config.cjs ./
 
-# Install backend dependencies
-RUN npm ci
+# Install root dependencies
+RUN npm install --only=production
 
-# Copy backend source
-COPY backend/src/ ./src/
+# Copy workspace files
+COPY backend/ ./backend/
+COPY frontend/ ./frontend/
 
-# Build backend
-RUN npm run build
+# Install workspace dependencies individually
+RUN npm install --workspace=backend
+RUN npm install --workspace=frontend
 
-# Copy database files manually
-RUN cp -r src/database/ dist/database/
+# Build backend first
+RUN npm run build --only=production --workspace=backend
+
+# Build frontend
+RUN npm run build --workspace=frontend
 
 # Verify Python and OR-Tools installation
 RUN python -c "from ortools.sat.python import cp_model; print('OR-Tools installed successfully')"
 
-# Frontend build stage
-FROM node:20-bullseye AS frontend-builder
-
-WORKDIR /app/frontend
-
-# Copy frontend files
-COPY frontend/package*.json ./
-COPY frontend/tsconfig.json ./
-
-# Install frontend dependencies
-RUN npm ci
-
-# Copy frontend source
-COPY frontend/src/ ./src/
-COPY frontend/public/ ./public/
-
-# Build frontend
-RUN npm run build
-
 # Production stage
 FROM node:20-bookworm
 
 WORKDIR /app
 
-# Install PM2 for process management
-RUN npm install -g pm2
+# Install system dependencies including gettext-base for envsubst
+RUN apt-get update && apt-get install -y gettext-base && \
+    rm -rf /var/lib/apt/lists/*
 
-# Create data directory for SQLite database with proper permissions
+RUN npm install -g pm2
 RUN mkdir -p /app/data
 
-# Copy backend built files
-COPY --from=backend-builder /app/backend/package*.json ./
-COPY --from=backend-builder /app/backend/dist/ ./dist/
-COPY --from=backend-builder /app/backend/node_modules/ ./node_modules/
+# Copy application files
+COPY --from=builder /app/backend/dist/ ./dist/
+COPY --from=builder /app/backend/package*.json ./
 
-# Copy frontend built files  
-COPY --from=frontend-builder /app/frontend/build/ ./frontend-build/
+COPY --from=builder /app/node_modules/ ./node_modules/
+COPY --from=builder /app/frontend/dist/ ./frontend-build/
 
-# Copy PM2 configuration
-COPY ecosystem.config.cjs ./
+COPY --from=builder /app/ecosystem.config.cjs ./
 
-# Create a non-root user and group - DEBIAN STYLE
+COPY --from=builder /app/backend/src/database/ ./dist/database/
+COPY --from=builder /app/backend/src/database/ ./database/
+
+# Copy init script and env template
+COPY docker-init.sh /usr/local/bin/
+COPY .env.template ./
+
+# Set execute permissions for init script
+RUN chmod +x /usr/local/bin/docker-init.sh
+
+# Create user and set permissions
 RUN groupadd -g 1001 nodejs && \
     useradd -m -u 1001 -s /bin/bash -g nodejs schichtplan && \
     chown -R schichtplan:nodejs /app && \
     chmod 755 /app && \
     chmod 775 /app/data
 
-# Set PM2 to use app directory instead of home directory
 ENV PM2_HOME=/app/.pm2
 
-USER schichtplan
+# Set entrypoint to init script and keep existing cmd
+ENTRYPOINT ["/usr/local/bin/docker-init.sh"]
+CMD ["pm2-runtime", "ecosystem.config.cjs"]
 
+USER schichtplan
 EXPOSE 3002
 
 HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
   CMD wget --no-verbose --tries=1 --spider http://localhost:3002/api/health || exit 1
-
-CMD ["pm2-runtime", "ecosystem.config.cjs"]

LICENSE-COMMERCIAL

@@ -15,7 +15,7 @@ This software, "Schichtenplaner", is offered under a dual licensing model.
    - Integration into commercial software or distributions
 
 To obtain a commercial license, please contact:
-📧 patrick@mahnke-hartmann.dev
+📧 dev.patrick@mahnke-hartmann.de
 or open an inquiry via GitHub: https://github.com/donpat1to/Schichtenplaner
 
 Without a valid commercial license, all commercial rights are reserved.

backend/package.json

@@ -4,6 +4,7 @@
   "type": "module",
   "scripts": {
     "dev": "npm run build && npx tsx src/server.ts",
+    "dev:single": "cross-env NODE_ENV=development TRUST_PROXY_ENABLED=false npx tsx src/server.ts",
     "build": "tsc",
     "start": "node dist/server.js",
     "prestart": "npm run build",
@@ -14,23 +15,27 @@
   },
   "dependencies": {
     "@types/bcrypt": "^6.0.0",
+    "@types/node": "24.9.2",
+    "vite":"7.1.12",
     "bcrypt": "^6.0.0",
     "bcryptjs": "^2.4.3",
-    "cors": "^2.8.5",
     "express": "^4.18.2",
     "jsonwebtoken": "^9.0.2",
     "sqlite3": "^5.1.6",
-    "uuid": "^9.0.0"
+    "uuid": "^9.0.0",
+    "express-rate-limit": "8.1.0",
+    "helmet": "8.1.0",
+    "express-validator": "7.3.0"
   },
   "devDependencies": {
     "@types/bcryptjs": "^2.4.2",
-    "@types/cors": "^2.8.13",
     "@types/express": "^4.17.17",
     "@types/jsonwebtoken": "^9.0.2",
     "@types/uuid": "^9.0.2",
     "@types/jest": "^29.5.0",
     "ts-node": "^10.9.0",
     "typescript": "^5.0.0",
-    "tsx": "^4.0.0"
+    "tsx": "^4.0.0",
+    "cross-env": "10.1.0"
   }
 }

backend/src/controllers/authController.ts

@@ -64,7 +64,7 @@ export const login = async (req: Request, res: Response) => {
       return res.status(400).json({ error: 'E-Mail und Passwort sind erforderlich' });
     }
 
-    // UPDATED: Get user from database with role from employee_roles table
+    // Get user from database with role from employee_roles table
     const user = await db.get<any>(
       `SELECT 
         e.id, e.email, e.password, e.firstname, e.lastname, 
@@ -155,7 +155,7 @@ export const getCurrentUser = async (req: Request, res: Response) => {
       return res.status(401).json({ error: 'Nicht authentifiziert' });
     }
 
-    // UPDATED: Get user with role from employee_roles table
+    // Get user with role from employee_roles table
     const user = await db.get<any>(
       `SELECT 
         e.id, e.email, e.firstname, e.lastname,

backend/src/controllers/employeeController.ts

@@ -1,5 +1,5 @@
 // backend/src/controllers/employeeController.ts
-import { Request, Response } from 'express';
+import { Response } from 'express';
 import { v4 as uuidv4 } from 'uuid';
 import bcrypt from 'bcryptjs';
 import { db } from '../services/databaseService.js';
@@ -314,6 +314,56 @@ export const updateEmployee = async (req: AuthRequest, res: Response): Promise<v
       return;
     }
 
+    // Check if user is trying to remove their own admin role
+    const currentUser = req.user;
+    if (currentUser?.userId === id && roles) {
+      const currentUserRoles = await db.all<{ role: string }>(
+        'SELECT role FROM employee_roles WHERE employee_id = ?',
+        [currentUser.userId]
+      );
+
+      const isCurrentlyAdmin = currentUserRoles.some(role => role.role === 'admin');
+      const willBeAdmin = roles.includes('admin');
+
+      if (isCurrentlyAdmin && !willBeAdmin) {
+        res.status(400).json({ error: 'You cannot remove your own admin role' });
+        return;
+      }
+    }
+
+    // Check admin count if roles are being updated
+    if (roles) {
+      try {
+        await checkAdminCount(id, roles);
+      } catch (error: any) {
+        res.status(400).json({ error: error.message });
+        return;
+      }
+    }
+
+    // Check if trying to deactivate the last admin
+    if (isActive === false) {
+      const isEmployeeAdmin = await db.get<{ count: number }>(
+        `SELECT COUNT(*) as count FROM employee_roles WHERE employee_id = ? AND role = 'admin'`,
+        [id]
+      );
+
+      if (isEmployeeAdmin && isEmployeeAdmin.count > 0) {
+        const otherAdminCount = await db.get<{ count: number }>(
+          `SELECT COUNT(*) as count 
+           FROM employee_roles er
+           JOIN employees e ON er.employee_id = e.id
+           WHERE er.role = 'admin' AND e.is_active = 1 AND er.employee_id != ?`,
+          [id]
+        );
+
+        if (!otherAdminCount || otherAdminCount.count === 0) {
+          res.status(400).json({ error: 'Cannot deactivate the last admin user' });
+          return;
+        }
+      }
+    }
+
     // Validate employee type if provided
     if (employeeType) {
       const validEmployeeType = await db.get(
@@ -438,7 +488,15 @@ export const deleteEmployee = async (req: AuthRequest, res: Response): Promise<v
     const { id } = req.params;
     console.log('🗑️ Starting deletion process for employee ID:', id);
 
-    // UPDATED: Check if employee exists with role from employee_roles
+    const currentUser = req.user;
+
+    // Prevent self-deletion
+    if (currentUser?.userId === id) {
+      res.status(400).json({ error: 'You cannot delete yourself' });
+      return;
+    }
+
+    // Check if employee exists with role from employee_roles
     const existingEmployee = await db.get<any>(`
       SELECT 
         e.id, e.email, e.firstname, e.lastname, e.is_active,
@@ -455,6 +513,26 @@ export const deleteEmployee = async (req: AuthRequest, res: Response): Promise<v
       return;
     }
 
+    const employeeRoles = await db.all<{ role: string }>(`
+      SELECT role FROM employee_roles WHERE employee_id = ?
+    `, [id]);
+
+    const isEmployeeAdmin = employeeRoles.some(role => role.role === 'admin');
+
+    // Check if this is the last admin
+    if (isEmployeeAdmin) {
+      const adminCount = await db.get<{ count: number }>(
+        `SELECT COUNT(*) as count 
+         FROM employee_roles 
+         WHERE role = 'admin'`
+      );
+
+      if (adminCount && adminCount.count <= 1) {
+        res.status(400).json({ error: 'Cannot delete the last admin user' });
+        return;
+      }
+    }
+
     console.log('📝 Found employee to delete:', existingEmployee);
 
     // Start transaction
@@ -511,7 +589,6 @@ export const deleteEmployee = async (req: AuthRequest, res: Response): Promise<v
       console.error('Error during deletion transaction:', error);
       throw error;
     }
-
   } catch (error) {
     console.error('Error deleting employee:', error);
     res.status(500).json({ error: 'Internal server error' });
@@ -558,13 +635,49 @@ export const updateAvailabilities = async (req: AuthRequest, res: Response): Pro
     const { employeeId } = req.params;
     const { planId, availabilities } = req.body;
 
-    // Check if employee exists
-    const existingEmployee = await db.get('SELECT id FROM employees WHERE id = ?', [employeeId]);
+    // Check if employee exists and get contract type
+    const existingEmployee = await db.get<any>(`
+      SELECT e.*, er.role 
+      FROM employees e
+      LEFT JOIN employee_roles er ON e.id = er.employee_id
+      WHERE e.id = ?
+    `, [employeeId]);
+
     if (!existingEmployee) {
       res.status(404).json({ error: 'Employee not found' });
       return;
     }
 
+    // Check if employee is active
+    if (!existingEmployee.is_active) {
+      res.status(400).json({ error: 'Cannot set availability for inactive employee' });
+      return;
+    }
+
+    // Validate contract type requirements
+    const availableCount = availabilities.filter((avail: any) =>
+      avail.preferenceLevel === 1 || avail.preferenceLevel === 2
+    ).length;
+
+    const contractType = existingEmployee.contract_type;
+
+    // Apply contract type minimum requirements
+    if (contractType === 'small' && availableCount < 2) {
+      res.status(400).json({
+        error: 'Employees with small contract must have at least 2 available shifts'
+      });
+      return;
+    }
+
+    if (contractType === 'large' && availableCount < 3) {
+      res.status(400).json({
+        error: 'Employees with large contract must have at least 3 available shifts'
+      });
+      return;
+    }
+
+    // Flexible contract has no minimum requirement
+
     await db.run('BEGIN TRANSACTION');
 
     try {
@@ -643,8 +756,8 @@ export const changePassword = async (req: AuthRequest, res: Response): Promise<v
       return;
     }
 
-    // For non-admin users, verify current password
-    if (currentUser?.role !== 'admin') {
+    // Verify current password
+    if (employee) {
       const isValidPassword = await bcrypt.compare(currentPassword, employee.password);
       if (!isValidPassword) {
         res.status(400).json({ error: 'Current password is incorrect' });
@@ -653,8 +766,8 @@ export const changePassword = async (req: AuthRequest, res: Response): Promise<v
     }
 
     // Validate new password
-    if (!newPassword || newPassword.length < 6) {
-      res.status(400).json({ error: 'New password must be at least 6 characters long' });
+    if (!newPassword || newPassword.length < 8) {
+      res.status(400).json({ error: 'New password must be at least 8 characters long' });
       return;
     }
 
@@ -700,3 +813,35 @@ export const updateLastLogin = async (req: AuthRequest, res: Response): Promise<
     res.status(500).json({ error: 'Internal server error' });
   }
 };
+
+const checkAdminCount = async (employeeId: string, newRoles: string[]): Promise<void> => {
+  try {
+    // Count current admins excluding the employee being updated
+    const adminCountResult = await db.get<{ count: number }>(
+      `SELECT COUNT(DISTINCT employee_id) as count 
+       FROM employee_roles 
+       WHERE role = 'admin' AND employee_id != ?`,
+      [employeeId]
+    );
+
+    const currentAdminCount = adminCountResult?.count || 0;
+
+    // Check ALL current roles for the employee
+    const currentEmployeeRoles = await db.all<{ role: string }>(
+      `SELECT role FROM employee_roles WHERE employee_id = ?`,
+      [employeeId]
+    );
+
+    const currentRoles = currentEmployeeRoles.map(role => role.role);
+    const isCurrentlyAdmin = currentRoles.includes('admin');
+    const willBeAdmin = newRoles.includes('admin');
+
+    // If removing admin role from the last admin, throw error
+    if (isCurrentlyAdmin && !willBeAdmin && currentAdminCount === 0) {
+      throw new Error('Cannot remove admin role from the last admin user');
+    }
+
+  } catch (error) {
+    throw error;
+  }
+};

backend/src/controllers/setupController.ts

@@ -1,7 +1,6 @@
 // backend/src/controllers/setupController.ts
 import { Request, Response } from 'express';
 import bcrypt from 'bcrypt';
-import { v4 as uuidv4 } from 'uuid';
 import { randomUUID } from 'crypto';
 import { db } from '../services/databaseService.js';
 
@@ -76,8 +75,8 @@ export const setupAdmin = async (req: Request, res: Response): Promise<void> =>
     }
 
     // Password length validation
-    if (password.length < 6) {
-      res.status(400).json({ error: 'Das Passwort muss mindestens 6 Zeichen lang sein' });
+    if (password.length < 8) {
+      res.status(400).json({ error: 'Das Passwort muss mindestens 8 Zeichen lang sein' });
       return;
     }
 

backend/src/controllers/shiftPlanController.ts

@@ -5,10 +5,9 @@ import { db } from '../services/databaseService.js';
 import { 
   CreateShiftPlanRequest, 
   UpdateShiftPlanRequest,
-  ShiftPlan
 } from '../models/ShiftPlan.js';
 import { AuthRequest } from '../middleware/auth.js';
-import { createPlanFromPreset, TEMPLATE_PRESETS } from '../models/defaults/shiftPlanDefaults.js';
+import { TEMPLATE_PRESETS } from '../models/defaults/shiftPlanDefaults.js';
 
 async function getPlanWithDetails(planId: string) {
   const plan = await db.get<any>(`

backend/src/database/schema.sql

@@ -1,3 +1,8 @@
+PRAGMA journal_mode = WAL;
+PRAGMA foreign_keys = ON;
+PRAGMA secure_delete = ON;
+PRAGMA auto_vacuum = INCREMENTAL;
+
 -- Employee Types
 CREATE TABLE IF NOT EXISTS employee_types (
   type TEXT PRIMARY KEY,

backend/src/middleware/Validation/Access.md

@@ -0,0 +1,25 @@
+## User Settings
+
+### \[UPDATE\] Personal availability
+* Only the employee themselves can manage their availability
+* Must select a valid shift plan with defined shifts
+* All changes require explicit save action
+
+### \[VIEW\] ShiftPlan assignments
+* Published plans show actual assignments
+* Draft plans show preview assignments (if calculated)
+* Regular users can only view, not modify assignments
+
+## System-wide
+
+### \[ACCESS\] Role-based restrictions
+* `admin`: Full access to all features
+* `maintenance`: Access to shift plans and employee management (except admin users)
+* `user`: Read-only access to shift plans, can manage own availability and profile
+
+### \[DATA\] Validation rules
+* Email addresses are automatically generated from firstname/lastname
+* Employee status (`isActive`) controls login and planning eligibility
+* Trainee status affects independence (`canWorkAlone`) automatically
+* Date ranges must be valid (start before end)
+* All required fields must be filled before form submission

backend/src/middleware/Validation/Assignment.md

@@ -0,0 +1,37 @@
+## Shift Assignment
+
+### \[ACTION: update scheduled shift\]
+* Requires valid scheduled shift ID
+* Only updates assignedEmployees array
+* Requires authentication with valid token
+* Handles both JSON and non-JSON responses
+
+### \[ACTION: assign shifts automatically\]
+* Requires shift plan, employees, and availabilities
+* Availability preferenceLevel must be 1, 2, or 3
+* Constraints must be an array (converts non-array to empty array)
+* All employees must have valid availability data
+
+### \[ACTION: get scheduled shifts\]
+* Requires valid plan ID
+* Automatically fixes data structure inconsistencies:
+  - timeSlotId mapping (handles both naming conventions)
+  - requiredEmployees fallback to 2 if missing
+  - assignedEmployees fallback to empty array if missing
+
+## Availability
+
+### [UPDATE] availability
+* planId: required valid UUID
+* availabilities: required array with strict validation:
+  - shiftId: valid UUID
+  - preferenceLevel: 0 (unavailable), 1 (available), or 2 (preferred)
+  - notes: optional, max 500 characters
+
+## Scheduling
+
+### [ACTION: generate schedule]
+* shiftPlan: required object with id (valid UUID)
+* employees: required array with at least one employee, each with valid UUID
+* availabilities: required array
+* constraints: optional array

backend/src/middleware/Validation/Authentication.md

@@ -0,0 +1,23 @@
+## Authentication
+
+### \[ACTION: login\]
+* Requires valid email and password format:
+  - Minimum 8 characters
+  - Must contain uppercase, lowercase, number and special character
+* Server validates credentials before issuing token
+* Token and employee data stored in localStorage upon success
+
+### \[ACTION: register\]
+* `Password` optional but strict validation:
+  - Minimum 8 characters
+  - Must contain uppercase, lowercase, number and special character
+* `firstname` 1-100 characters and must not be empty
+* `lastname` 1-100 characters and must not be empty
+* Requires valid email
+* Role is optional during registration
+* Automatically logs in user after successful registration
+
+### \[ACTION: access protected resources\]
+* Requires valid JWT token in Authorization header
+* Token is automatically retrieved from localStorage
+* Unauthorized requests (401) trigger automatic logout

backend/src/middleware/Validation/DataIntegrity

@@ -0,0 +1,23 @@
+## Data Integrity
+
+### \[GENERAL\] API communication
+* All fetch requests include error handling
+* Failed responses throw descriptive errors
+* Token validation before protected operations
+* Automatic localStorage cleanup on logout
+
+### \[GENERAL\] data persistence
+* Employee data cached in localStorage after login
+* Token automatically retrieved from localStorage
+* Data structure normalization for scheduled shifts
+
+### \[GENERAL\] error handling
+* Network errors are caught and logged
+* HTTP errors include status codes and messages
+* Failed authentication triggers cleanup and logout
+
+## Role & Permission Notes
+* The frontend services don't explicitly restrict actions by role
+* Role-based restrictions are likely handled by the backend
+* Frontend assumes user has permissions for requested operations
+* 401 responses indicate insufficient permissions at backend level

backend/src/middleware/Validation/Employee.md

@@ -0,0 +1,75 @@
+## Employee Management
+
+### \[CREATE/UPDATE\] employee
+* All employee operations require authentication
+* Password changes require current password + new password
+* Only authenticated users can create/update employees
+
+### \[ACTION: delete employee\]
+* Requires authentication
+* Server validates permissions before deletion
+
+### \[ACTION: update availability\]
+* Requires employee ID and plan ID
+* Availability updates must include valid preference levels
+* Only authenticated users can update availabilities
+
+### \[ACTION: update last login\]
+* Requires employee ID
+* Fails silently if update fails (logs error but doesn`t block user)
+
+## Employee
+
+### \[CREATE\] Employee
+* `firstname` 1-100 characters and must not be empty
+* `lastname` 1-100 characters and must not be empty
+* `password` must be at least 8 characters (in create mode)
+* `employeeType` must be `manager`, `personell`, `apprentice`, or `guest`
+* `canWorkAlone` optional boolean
+* `isTrainee` optional boolean
+* `isActive` optional boolean (default true)
+* Contract type validation:
+  * `manager`, `apprentice` => `contractType` = flexible
+  * `guest` => `contractType` = undefined/NONE
+  * `personell` => `contractType` = small || large
+
+### \[UPDATE\] Employee profile
+* `firstname` 1-100 characters and must not be empty
+* `lastname` 1-100 characters and must not be empty
+* `employeeType` must be valid type if provided
+* `contractType` must be valid type if provided
+* `roles` must be valid array of roles if provided
+* Only the employee themselves or admins can update
+
+### \[UPDATE\] Employee password
+* `newPassword` optional but strict validation:
+  - Minimum 8 characters
+  - Must contain uppercase, lowercase, number and special character
+* `newPassword` must match `confirmPassword`
+* For admin password reset: no `currentPassword` required
+* For self-password change: `currentPassword` required
+
+### \[UPDATE\] Employee roles
+* Only users with role `admin` can modify roles
+* At least one employee must maintain `admin` role
+* Users cannot remove their own admin role
+
+### \[UPDATE\] Employee availability
+* Only active employees can set availability
+* Contract type requirements:
+  * `small` contract: minimum 2 available shifts (preference level 1 or 2)
+  * `large` contract: minimum 3 available shifts (preference level 1 or 2)
+  * `flexible` contract: no minimum requirement
+* Availability can only be set for valid shift patterns in selected plan
+* `shiftId` must be valid and exist in the current plan
+
+### \[ACTION: delete\] Employee
+* Only users with role `admin` can delete employees
+* Cannot delete yourself
+* Cannot delete the last admin user
+* User confirmation required before deletion
+
+### \[ACTION: edit\] Employee
+* Admins can edit all employees
+* Maintenance users can edit non-admin employees or themselves
+* Regular users can only edit themselves

backend/src/middleware/Validation/Shiftplan.md

@@ -0,0 +1,66 @@
+## Shift Plan Management
+
+### \[CREATE\] shift plan
+* All operations require authentication
+* 401 responses trigger automatic logout
+* Scheduled shifts array is guaranteed to exist (empty array if none)
+
+### \[CREATE\] shift plan from preset
+* presetName must match existing TEMPLATE_PRESETS
+* Requires name, startDate, and endDate
+* isTemplate is optional (defaults to false)
+
+### \[UPDATE\] shift plan
+* Requires valid shift plan ID
+* Partial updates allowed
+* Authentication required
+
+### \[ACTION: delete shift plan\]
+* Requires authentication
+* 401 responses trigger automatic logout
+
+### \[ACTION: regenerate scheduled shifts\]
+* Requires valid plan ID
+* Authentication required
+* Fails silently if regeneration fails (logs error but continues)
+
+### \[ACTION: clear assignments\]
+* Requires valid plan ID
+* Authentication required
+* Clears all employee assignments from scheduled shifts
+
+## ShiftPlan
+
+### \[CREATE\] ShiftPlan from template
+* `planName` must not be empty
+* `startDate` must be set
+* `endDate` must be set
+* `endDate` must be after `startDate`
+* `selectedPreset` must be chosen (template must be selected)
+* Only available template presets can be used
+
+### \[ACTION: publish\] ShiftPlan
+* Plan must be in 'draft' status
+* All active employees must have set their availabilities for the plan
+* Only users with roles \['admin', 'maintenance'\] can publish
+* Assignment algorithm must not have critical violations (ERROR or ❌ KRITISCH)
+* employee && employee.contract_type === small => mind. 1 mal availability === 1 || availability === 2
+* employee && employee.contract_type === large => mind. 3 mal availability === 1 || availability === 2
+
+### \[ACTION: recreate assignments\]
+* Plan must be in 'published' status
+* Only users with roles \['admin', 'maintenance'\] can recreate
+* User confirmation required before clearing all assignments
+
+### \[ACTION: delete\] ShiftPlan
+* Only users with roles \['admin', 'maintenance'\] can delete
+* User confirmation required before deletion
+
+### \[ACTION: edit\] ShiftPlan
+* Only users with roles \['admin', 'maintenance'\] can edit
+* Can only edit plans in 'draft' status
+
+### \[UPDATE\] ShiftPlan shifts
+* `timeSlotId` must be selected from available time slots
+* `requiredEmployees` must be at least 1
+* `dayOfWeek` must be between 1-7

backend/src/middleware/auth.ts

@@ -52,3 +52,35 @@ export const requireRole = (roles: string[]) => {
     next();
   };
 };
+
+export const getClientIP = (req: Request): string => {
+  const trustedHeader = process.env.TRUSTED_PROXY_HEADER || 'x-forwarded-for';
+  const forwarded = req.headers[trustedHeader];
+  const realIp = req.headers['x-real-ip'];
+  
+  if (forwarded) {
+    if (Array.isArray(forwarded)) {
+      return forwarded[0].split(',')[0].trim();
+    } else if (typeof forwarded === 'string') {
+      return forwarded.split(',')[0].trim();
+    }
+  }
+  
+  if (realIp) {
+    return realIp.toString();
+  }
+  
+  return req.socket.remoteAddress || req.ip || 'unknown';
+};
+
+export const ipSecurityCheck = (req: AuthRequest, res: Response, next: NextFunction): void => {
+  const clientIP = getClientIP(req);
+  
+  // Log suspicious activity
+  const suspiciousPaths = ['/api/auth/login', '/api/auth/register'];
+  if (suspiciousPaths.includes(req.path)) {
+    console.log(`🔐 Auth attempt from IP: ${clientIP}, Path: ${req.path}`);
+  }
+  
+  next();
+}

backend/src/middleware/rateLimit.ts

@@ -0,0 +1,145 @@
+import rateLimit from 'express-rate-limit';
+import { Request } from 'express';
+
+// Secure IP extraction that works with proxy settings
+const getClientIP = (req: Request): string => {
+  // Read from environment which header to trust
+  const trustedHeader = process.env.TRUSTED_PROXY_HEADER || 'x-forwarded-for';
+  
+  const forwarded = req.headers[trustedHeader];
+  const realIp = req.headers['x-real-ip'];
+  const cfConnectingIp = req.headers['cf-connecting-ip']; // Cloudflare
+  
+  // If we have a forwarded header and trust proxy is configured
+  if (forwarded) {
+    if (Array.isArray(forwarded)) {
+      const firstIP = forwarded[0].split(',')[0].trim();
+      console.log(`🔍 Extracted IP from ${trustedHeader}: ${firstIP} (from: ${forwarded[0]})`);
+      return firstIP;
+    } else if (typeof forwarded === 'string') {
+      const firstIP = forwarded.split(',')[0].trim();
+      console.log(`🔍 Extracted IP from ${trustedHeader}: ${firstIP} (from: ${forwarded})`);
+      return firstIP;
+    }
+  }
+  
+  // Cloudflare support
+  if (cfConnectingIp) {
+    console.log(`🔍 Using Cloudflare IP: ${cfConnectingIp}`);
+    return cfConnectingIp.toString();
+  }
+  
+  // Fallback to x-real-ip
+  if (realIp) {
+    console.log(`🔍 Using x-real-ip: ${realIp}`);
+    return realIp.toString();
+  }
+  
+  // Final fallback to connection remote address
+  const remoteAddress = req.socket.remoteAddress || req.ip || 'unknown';
+  console.log(`🔍 Using remote address: ${remoteAddress}`);
+  return remoteAddress;
+};
+
+// Helper to check if request should be limited
+const shouldSkipLimit = (req: Request): boolean => {
+  const skipPaths = [
+    '/api/health', 
+    '/api/setup/status',
+    '/api/auth/validate'
+  ];
+  
+  // Skip for successful GET requests (data fetching)
+  if (req.method === 'GET' && req.path.startsWith('/api/')) {
+    return true;
+  }
+  
+  // Skip for whitelisted IPs from environment
+  const whitelist = process.env.RATE_LIMIT_WHITELIST?.split(',') || [];
+  const clientIP = getClientIP(req);
+  if (whitelist.includes(clientIP)) {
+    console.log(`✅ IP whitelisted: ${clientIP}`);
+    return true;
+  }
+  
+  return skipPaths.includes(req.path);
+};
+
+// Environment-based configuration
+const getRateLimitConfig = () => {
+  const isProduction = process.env.NODE_ENV === 'production';
+  
+  return {
+    windowMs: parseInt(process.env.RATE_LIMIT_WINDOW_MS || '900000'), // 15 minutes default
+    max: isProduction 
+      ? parseInt(process.env.RATE_LIMIT_MAX_REQUESTS || '100')  // Stricter in production
+      : parseInt(process.env.RATE_LIMIT_MAX_REQUESTS || '1000'), // More lenient in development
+    
+    // Development-specific relaxations
+    skip: (req: Request) => {
+      // Skip all GET requests in development for easier testing
+      if (!isProduction && req.method === 'GET') {
+        return true;
+      }
+      
+      return shouldSkipLimit(req);
+    }
+  };
+};
+
+// Main API limiter - nur für POST/PUT/DELETE
+export const apiLimiter = rateLimit({
+  ...getRateLimitConfig(),
+  message: { 
+    error: 'Zu viele Anfragen, bitte verlangsamen Sie Ihre Aktionen' 
+  },
+  standardHeaders: true,
+  legacyHeaders: false,
+  keyGenerator: (req) => getClientIP(req),
+  handler: (req, res) => {
+    const clientIP = getClientIP(req);
+    console.warn(`🚨 Rate limit exceeded for IP: ${clientIP}, Path: ${req.path}, Method: ${req.method}`);
+    
+    res.status(429).json({ 
+      error: 'Zu viele Anfragen',
+      message: 'Bitte versuchen Sie es später erneut',
+      retryAfter: '15 Minuten',
+      clientIP: process.env.NODE_ENV === 'development' ? clientIP : undefined // Only expose IP in dev
+    });
+  }
+});
+
+// Strict limiter for auth endpoints
+export const authLimiter = rateLimit({
+  windowMs: 15 * 60 * 1000,
+  max: parseInt(process.env.AUTH_RATE_LIMIT_MAX_REQUESTS || '5'),
+  message: { 
+    error: 'Zu viele Login-Versuche, bitte versuchen Sie es später erneut' 
+  },
+  standardHeaders: true,
+  legacyHeaders: false,
+  skipSuccessfulRequests: true,
+  keyGenerator: (req) => getClientIP(req),
+  handler: (req, res) => {
+    const clientIP = getClientIP(req);
+    console.warn(`🚨 Auth rate limit exceeded for IP: ${clientIP}`);
+    
+    res.status(429).json({ 
+      error: 'Zu viele Login-Versuche',
+      message: 'Aus Sicherheitsgründen wurde Ihr Konto temporär gesperrt',
+      retryAfter: '15 Minuten'
+    });
+  }
+});
+
+// Separate limiter for expensive endpoints
+export const expensiveEndpointLimiter = rateLimit({
+  windowMs: 15 * 60 * 1000,
+  max: parseInt(process.env.EXPENSIVE_ENDPOINT_LIMIT || '10'),
+  message: {
+    error: 'Zu viele Anfragen für diese Ressource'
+  },
+  standardHeaders: true,
+  legacyHeaders: false,
+  keyGenerator: (req) => getClientIP(req)
+});

backend/src/middleware/validation.ts

@@ -0,0 +1,550 @@
+import { body, validationResult, param, query } from 'express-validator';
+import { Request, Response, NextFunction } from 'express';
+
+// ===== AUTH VALIDATION =====
+export const validateLogin = [
+  body('email')
+    .isEmail()
+    .withMessage('Must be a valid email')
+    .normalizeEmail(),
+
+  body('password')
+    .optional()
+    .isLength({ min: 8 })
+    .withMessage('Password must be at least 8 characters')
+    .matches(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?])/)
+    .withMessage('Password must contain uppercase, lowercase, number and special character'),
+];
+
+export const validateRegister = [
+  body('firstname')
+    .isLength({ min: 1, max: 100 })
+    .withMessage('First name must be between 1-100 characters')
+    .notEmpty()
+    .withMessage('First name must not be empty')
+    .trim()
+    .escape(),
+
+  body('lastname')
+    .isLength({ min: 1, max: 100 })
+    .withMessage('Last name must be between 1-100 characters')
+    .notEmpty()
+    .withMessage('Last name must not be empty')
+    .trim()
+    .escape(),
+
+  body('password')
+    .optional()
+    .isLength({ min: 8 })
+    .withMessage('Password must be at least 8 characters')
+    .matches(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?])/)
+    .withMessage('Password must contain uppercase, lowercase, number and special character'),
+];
+
+// ===== EMPLOYEE VALIDATION =====
+export const validateEmployee = [
+  body('firstname')
+    .isLength({ min: 1, max: 100 })
+    .withMessage('First name must be between 1-100 characters')
+    .notEmpty()
+    .withMessage('First name must not be empty')
+    .trim()
+    .escape(),
+
+  body('lastname')
+    .isLength({ min: 1, max: 100 })
+    .withMessage('Last name must be between 1-100 characters')
+    .notEmpty()
+    .withMessage('Last name must not be empty')
+    .trim()
+    .escape(),
+
+  body('password')
+    .optional()
+    .isLength({ min: 8 })
+    .withMessage('Password must be at least 8 characters')
+    .matches(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?])/)
+    .withMessage('Password must contain uppercase, lowercase, number and special character'),
+
+  body('employeeType')
+    .isIn(['manager', 'personell', 'apprentice', 'guest'])
+    .withMessage('Employee type must be manager, personell, apprentice or guest'),
+
+  body('contractType')
+    .custom((value, { req }) => {
+      const employeeType = req.body.employeeType;
+
+      // Manager, apprentice => contractType must be flexible
+      if (['manager', 'apprentice'].includes(employeeType)) {
+        if (value !== 'flexible') {
+          throw new Error(`contractType must be 'flexible' for employeeType: ${employeeType}`);
+        }
+      }
+      // Guest => contractType must be undefined/NONE
+      else if (employeeType === 'guest') {
+        if (value !== undefined && value !== null) {
+          throw new Error(`contractType is not allowed for employeeType: ${employeeType}`);
+        }
+      }
+      // Personell => contractType must be small or large
+      else if (employeeType === 'personell') {
+        if (!['small', 'large'].includes(value)) {
+          throw new Error(`contractType must be 'small' or 'large' for employeeType: ${employeeType}`);
+        }
+      }
+
+      return true;
+    }),
+
+  body('contractType')
+    .optional()
+    .isIn(['small', 'large', 'flexible'])
+    .withMessage('Contract type must be small, large or flexible'),
+
+  body('roles')
+    .optional()
+    .isArray()
+    .withMessage('Roles must be an array'),
+
+  body('roles.*')
+    .optional()
+    .isIn(['admin', 'maintenance', 'user'])
+    .withMessage('Invalid role. Allowed: admin, maintenance, user'),
+
+  body('canWorkAlone')
+    .optional()
+    .isBoolean()
+    .withMessage('canWorkAlone must be a boolean'),
+
+  body('isTrainee')
+    .optional()
+    .isBoolean()
+    .withMessage('isTrainee must be a boolean'),
+
+  body('isActive')
+    .optional()
+    .isBoolean()
+    .withMessage('isActive must be a boolean')
+];
+
+export const validateEmployeeUpdate = [
+  body('firstname')
+    .optional()
+    .isLength({ min: 1, max: 100 })
+    .withMessage('First name must be between 1-100 characters')
+    .notEmpty()
+    .withMessage('First name must not be empty')
+    .trim()
+    .escape(),
+
+  body('lastname')
+    .optional()
+    .isLength({ min: 1, max: 100 })
+    .withMessage('Last name must be between 1-100 characters')
+    .notEmpty()
+    .withMessage('Last name must not be empty')
+    .trim()
+    .escape(),
+
+  body('employeeType')
+    .optional()
+    .isIn(['manager', 'personell', 'apprentice', 'guest'])
+    .withMessage('Employee type must be manager, personell, apprentice or guest'),
+
+  body('contractType')
+    .optional()
+    .custom((value, { req }) => {
+      const employeeType = req.body.employeeType;
+      if (!employeeType) return true; // Skip if employeeType not provided
+
+      // Same validation logic as create
+      if (['manager', 'apprentice'].includes(employeeType)) {
+        if (value !== 'flexible') {
+          throw new Error(`contractType must be 'flexible' for employeeType: ${employeeType}`);
+        }
+      }
+      else if (employeeType === 'guest') {
+        if (value !== undefined && value !== null) {
+          throw new Error(`contractType is not allowed for employeeType: ${employeeType}`);
+        }
+      }
+      else if (employeeType === 'personell') {
+        if (!['small', 'large'].includes(value)) {
+          throw new Error(`contractType must be 'small' or 'large' for employeeType: ${employeeType}`);
+        }
+      }
+
+      return true;
+    }),
+
+  body('roles')
+    .optional()
+    .isArray()
+    .withMessage('Roles must be an array'),
+
+  body('roles.*')
+    .optional()
+    .isIn(['admin', 'maintenance', 'user'])
+    .withMessage('Invalid role. Allowed: admin, maintenance, user'),
+
+  body('canWorkAlone')
+    .optional()
+    .isBoolean()
+    .withMessage('canWorkAlone must be a boolean'),
+
+  body('isTrainee')
+    .optional()
+    .isBoolean()
+    .withMessage('isTrainee must be a boolean'),
+
+  body('isActive')
+    .optional()
+    .isBoolean()
+    .withMessage('isActive must be a boolean')
+];
+
+export const validateChangePassword = [
+  body('currentPassword')
+    .optional()
+    .isLength({ min: 1 })
+    .withMessage('Current password is required for self-password change'),
+
+  body('newPassword')
+    .isLength({ min: 8 })
+    .withMessage('Password must be at least 8 characters')
+    .matches(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?])/)
+    .withMessage('Password must contain uppercase, lowercase, number and special character'),
+
+  body('confirmPassword')
+    .custom((value, { req }) => {
+      if (value !== req.body.newPassword) {
+        throw new Error('Passwords do not match');
+      }
+      return true;
+    })
+];
+
+// ===== SHIFT PLAN VALIDATION =====
+export const validateShiftPlan = [
+  body('name')
+    .isLength({ min: 1, max: 200 })
+    .withMessage('Name must be between 1-200 characters')
+    .trim()
+    .escape(),
+
+  body('description')
+    .optional()
+    .isLength({ max: 1000 })
+    .withMessage('Description cannot exceed 1000 characters')
+    .trim()
+    .escape(),
+
+  body('startDate')
+    .optional()
+    .isISO8601()
+    .withMessage('Must be a valid date (ISO format)'),
+
+  body('endDate')
+    .optional()
+    .isISO8601()
+    .withMessage('Must be a valid date (ISO format)'),
+
+  body('isTemplate')
+    .optional()
+    .isBoolean()
+    .withMessage('isTemplate must be a boolean'),
+
+  body('status')
+    .optional()
+    .isIn(['draft', 'published', 'archived', 'template'])
+    .withMessage('Status must be draft, published, archived or template'),
+
+  body('timeSlots')
+    .optional()
+    .isArray()
+    .withMessage('Time slots must be an array'),
+
+  body('timeSlots.*.name')
+    .isLength({ min: 1, max: 100 })
+    .withMessage('Time slot name must be between 1-100 characters')
+    .trim()
+    .escape(),
+
+  body('timeSlots.*.startTime')
+    .matches(/^([0-1]?[0-9]|2[0-3]):[0-5][0-9]$/)
+    .withMessage('Start time must be in HH:MM format'),
+
+  body('timeSlots.*.endTime')
+    .matches(/^([0-1]?[0-9]|2[0-3]):[0-5][0-9]$/)
+    .withMessage('End time must be in HH:MM format'),
+
+  body('timeSlots.*.description')
+    .optional()
+    .isLength({ max: 500 })
+    .withMessage('Time slot description cannot exceed 500 characters')
+    .trim()
+    .escape(),
+
+  body('shifts')
+    .optional()
+    .isArray()
+    .withMessage('Shifts must be an array'),
+
+  body('shifts.*.dayOfWeek')
+    .isInt({ min: 1, max: 7 })
+    .withMessage('Day of week must be between 1-7 (Monday-Sunday)'),
+
+  body('shifts.*.timeSlotId')
+    .isUUID()
+    .withMessage('Time slot ID must be a valid UUID'),
+
+  body('shifts.*.requiredEmployees')
+    .isInt({ min: 0 })
+    .withMessage('Required employees must be a positive integer'),
+
+  body('shifts.*.color')
+    .optional()
+    .isHexColor()
+    .withMessage('Color must be a valid hex color')
+];
+
+export const validateShiftPlanUpdate = [
+  body('name')
+    .optional()
+    .isLength({ min: 1, max: 200 })
+    .withMessage('Name must be between 1-200 characters')
+    .trim()
+    .escape(),
+
+  body('description')
+    .optional()
+    .isLength({ max: 1000 })
+    .withMessage('Description cannot exceed 1000 characters')
+    .trim()
+    .escape(),
+
+  body('startDate')
+    .optional()
+    .isISO8601()
+    .withMessage('Must be a valid date (ISO format)'),
+
+  body('endDate')
+    .optional()
+    .isISO8601()
+    .withMessage('Must be a valid date (ISO format)'),
+
+  body('status')
+    .optional()
+    .isIn(['draft', 'published', 'archived', 'template'])
+    .withMessage('Status must be draft, published, archived or template'),
+
+  body('timeSlots')
+    .optional()
+    .isArray()
+    .withMessage('Time slots must be an array'),
+
+  body('shifts')
+    .optional()
+    .isArray()
+    .withMessage('Shifts must be an array')
+];
+
+export const validateCreateFromPreset = [
+  body('presetName')
+    .isLength({ min: 1 })
+    .withMessage('Preset name is required')
+    .isIn(['GENERAL_STANDARD', 'ZEBRA_STANDARD'])
+    .withMessage('Invalid preset name'),
+
+  body('name')
+    .isLength({ min: 1, max: 200 })
+    .withMessage('Name must be between 1-200 characters')
+    .trim()
+    .escape(),
+
+  body('startDate')
+    .isISO8601()
+    .withMessage('Must be a valid date (ISO format)')
+    .custom((value, { req }) => {
+      if (req.body.endDate && new Date(value) > new Date(req.body.endDate)) {
+        throw new Error('Start date must be before end date');
+      }
+      return true;
+    }),
+
+  body('endDate')
+    .isISO8601()
+    .withMessage('Must be a valid date (ISO format)')
+    .custom((value, { req }) => {
+      if (req.body.startDate && new Date(value) < new Date(req.body.startDate)) {
+        throw new Error('End date must be after start date');
+      }
+      return true;
+    }),
+
+  body('isTemplate')
+    .optional()
+    .isBoolean()
+    .withMessage('isTemplate must be a boolean')
+];
+
+// ===== SCHEDULED SHIFTS VALIDATION =====
+export const validateScheduledShiftUpdate = [
+  body('assignedEmployees')
+    .isArray()
+    .withMessage('assignedEmployees must be an array'),
+
+  body('assignedEmployees.*')
+    .isUUID()
+    .withMessage('Each assigned employee must be a valid UUID'),
+
+  body('requiredEmployees')
+    .optional()
+    .isInt({ min: 0 })
+    .withMessage('Required employees must be a positive integer')
+];
+
+// ===== SETUP VALIDATION =====
+export const validateSetupAdmin = [
+  body('firstname')
+    .isLength({ min: 1, max: 100 })
+    .withMessage('First name must be between 1-100 characters')
+    .trim()
+    .escape(),
+
+  body('lastname')
+    .isLength({ min: 1, max: 100 })
+    .withMessage('Last name must be between 1-100 characters')
+    .trim()
+    .escape(),
+
+  body('password')
+    .optional()
+    .isLength({ min: 8 })
+    .withMessage('Password must be at least 8 characters')
+    .matches(/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?])/)
+    .withMessage('Password must contain uppercase, lowercase, number and special character'),
+];
+
+// ===== SCHEDULING VALIDATION =====
+export const validateSchedulingRequest = [
+  body('shiftPlan')
+    .isObject()
+    .withMessage('Shift plan is required'),
+
+  body('shiftPlan.id')
+    .isUUID()
+    .withMessage('Shift plan ID must be a valid UUID'),
+
+  body('employees')
+    .isArray({ min: 1 })
+    .withMessage('At least one employee is required'),
+
+  body('employees.*.id')
+    .isUUID()
+    .withMessage('Each employee must have a valid UUID'),
+
+  body('availabilities')
+    .isArray()
+    .withMessage('Availabilities must be an array'),
+
+  body('constraints')
+    .optional()
+    .isArray()
+    .withMessage('Constraints must be an array')
+];
+
+// ===== AVAILABILITY VALIDATION =====
+export const validateAvailabilities = [
+  body('planId')
+    .isUUID()
+    .withMessage('Plan ID must be a valid UUID'),
+
+  body('availabilities')
+    .isArray()
+    .withMessage('Availabilities must be an array')
+    .custom((availabilities, { req }) => {
+      // Count available shifts (preference level 1 or 2)
+      const availableCount = availabilities.filter((avail: any) =>
+        avail.preferenceLevel === 1 || avail.preferenceLevel === 2
+      ).length;
+
+      // Basic validation - at least one available shift
+      if (availableCount === 0) {
+        throw new Error('At least one available shift is required');
+      }
+
+      return true;
+    }),
+
+  body('availabilities.*.shiftId')
+    .isUUID()
+    .withMessage('Each shift ID must be a valid UUID'),
+
+  body('availabilities.*.preferenceLevel')
+    .isInt({ min: 0, max: 2 })
+    .withMessage('Preference level must be 0 (unavailable), 1 (available), or 2 (preferred)'),
+
+  body('availabilities.*.notes')
+    .optional()
+    .isLength({ max: 500 })
+    .withMessage('Notes cannot exceed 500 characters')
+    .trim()
+    .escape()
+];
+
+// ===== COMMON VALIDATORS =====
+export const validateId = [
+  param('id')
+    .isUUID()
+    .withMessage('Must be a valid UUID')
+];
+
+export const validateEmployeeId = [
+  param('employeeId')
+    .isUUID()
+    .withMessage('Must be a valid UUID')
+];
+
+export const validatePlanId = [
+  param('planId')
+    .isUUID()
+    .withMessage('Must be a valid UUID')
+];
+
+export const validatePagination = [
+  query('page')
+    .optional()
+    .isInt({ min: 1 })
+    .withMessage('Page must be a positive integer'),
+
+  query('limit')
+    .optional()
+    .isInt({ min: 1, max: 100 })
+    .withMessage('Limit must be between 1-100'),
+
+  query('includeInactive')
+    .optional()
+    .isBoolean()
+    .withMessage('includeInactive must be a boolean')
+];
+
+// ===== MIDDLEWARE TO CHECK VALIDATION RESULTS =====
+export const handleValidationErrors = (req: Request, res: Response, next: NextFunction) => {
+  const errors = validationResult(req);
+
+  if (!errors.isEmpty()) {
+    const errorMessages = errors.array().map(error => ({
+      field: error.type === 'field' ? error.path : error.type,
+      message: error.msg,
+      value: error.msg
+    }));
+
+    return res.status(400).json({
+      error: 'Validation failed',
+      details: errorMessages
+    });
+  }
+
+  next();
+};

backend/src/models/helpers/employeeHelpers.ts

@@ -18,12 +18,12 @@ function generateEmail(firstname: string, lastname: string): string {
   return `${cleanFirstname}.${cleanLastname}@sp.de`;
 }
 
-// UPDATED: Validation for new employee model with employee types
+// Validation for new employee model with employee types
 export function validateEmployeeData(employee: CreateEmployeeRequest): string[] {
   const errors: string[] = [];
 
-  if (employee.password?.length < 6) {
-    errors.push('Password must be at least 6 characters long');
+  if (employee.password?.length < 8) {
+    errors.push('Password must be at least 8 characters long');
   }
 
   if (!employee.firstname?.trim() || employee.firstname.trim().length < 2) {
@@ -71,7 +71,7 @@ export function generateEmployeeEmail(firstname: string, lastname: string): stri
   return generateEmail(firstname, lastname);
 }
 
-// UPDATED: Business logic helpers for new employee types
+// Business logic helpers for new employee types
 export const isManager = (employee: Employee): boolean =>
   employee.employeeType === 'manager';
 
@@ -90,7 +90,7 @@ export const isInternal = (employee: Employee): boolean =>
 export const isExternal = (employee: Employee): boolean =>
   employee.employeeType === 'guest';
 
-// UPDATED: Trainee logic - now based on isTrainee field for personell type
+// Trainee logic - now based on isTrainee field for personell type
 export const isTrainee = (employee: Employee): boolean =>
   employee.employeeType === 'personell' && employee.isTrainee;
 
@@ -107,7 +107,7 @@ export const isMaintenance = (employee: Employee): boolean =>
 export const isUser = (employee: Employee): boolean =>
   employee.roles?.includes('user') || false;
 
-// UPDATED: Work alone permission - managers and experienced personell can work alone
+// Work alone permission - managers and experienced personell can work alone
 export const canEmployeeWorkAlone = (employee: Employee): boolean =>
   employee.canWorkAlone && (isManager(employee) || isExperienced(employee));
 
@@ -134,7 +134,7 @@ export function validateAvailabilityData(availability: Omit<EmployeeAvailability
   return errors;
 }
 
-// UPDATED: Helper to get employee type category
+// Helper to get employee type category
 export const getEmployeeCategory = (employee: Employee): 'internal' | 'external' => {
   return isInternal(employee) ? 'internal' : 'external';
 };

backend/src/models/helpers/shiftPlanHelpers.ts

@@ -78,7 +78,7 @@ export function calculateTotalRequiredEmployees(plan: ShiftPlan): number {
   return plan.shifts.reduce((total, shift) => total + shift.requiredEmployees, 0);
 }
 
-// UPDATED: Get scheduled shift by date and time slot
+// Get scheduled shift by date and time slot
 export function getScheduledShiftByDateAndTime(
   plan: ShiftPlan, 
   date: string, 

backend/src/models/scheduling.ts

@@ -2,7 +2,7 @@
 import { Employee } from './Employee.js';
 import { ShiftPlan } from './ShiftPlan.js';
 
-// Updated Availability interface to match new schema
+// Availability interface
 export interface Availability {
   id: string;
   employeeId: string;

backend/src/routes/auth.ts

@@ -8,12 +8,13 @@ import {
   validateToken 
 } from '../controllers/authController.js';
 import { authMiddleware } from '../middleware/auth.js';
+import { validateLogin, validateRegister, handleValidationErrors } from '../middleware/validation.js';
 
 const router = express.Router();
 
 // Public routes
-router.post('/login', login);
-router.post('/register', register);
+router.post('/login', validateLogin, handleValidationErrors, login);
+router.post('/register', validateRegister, handleValidationErrors, register);
 router.get('/validate', validateToken);
 
 // Protected routes (require authentication)

backend/src/routes/employees.ts

@@ -1,4 +1,3 @@
-// backend/src/routes/employees.ts
 import express from 'express';
 import { authMiddleware, requireRole } from '../middleware/auth.js';
 import {
@@ -12,6 +11,16 @@ import {
   changePassword,
   updateLastLogin
 } from '../controllers/employeeController.js';
+import {
+  handleValidationErrors,
+  validateEmployee,
+  validateEmployeeUpdate,
+  validateChangePassword,
+  validateId,
+  validateEmployeeId,
+  validateAvailabilities,
+  validatePagination
+} from '../middleware/validation.js';
 
 const router = express.Router();
 
@@ -19,16 +28,18 @@ const router = express.Router();
 router.use(authMiddleware);
 
 // Employee CRUD Routes
-router.get('/', authMiddleware, getEmployees);
-router.get('/:id', requireRole(['admin', 'maintenance']), getEmployee);
-router.post('/', requireRole(['admin']), createEmployee);
-router.put('/:id', requireRole(['admin', 'maintenance']), updateEmployee);
-router.delete('/:id', requireRole(['admin']), deleteEmployee);
-router.put('/:id/password', authMiddleware, changePassword);
-router.put('/:id/last-login', authMiddleware, updateLastLogin);
+router.get('/', validatePagination, handleValidationErrors, authMiddleware, getEmployees);
+router.get('/:id', validateId, handleValidationErrors, requireRole(['admin', 'maintenance']), getEmployee);
+router.post('/', validateEmployee, handleValidationErrors, requireRole(['admin']), createEmployee);
+router.put('/:id', validateId, validateEmployeeUpdate, handleValidationErrors, requireRole(['admin', 'maintenance']), updateEmployee);
+router.delete('/:id', validateId, handleValidationErrors, requireRole(['admin']), deleteEmployee);
+
+// Password & Login Routes
+router.put('/:id/password', validateId, validateChangePassword, handleValidationErrors, authMiddleware, changePassword);
+router.put('/:id/last-login', validateId, handleValidationErrors, authMiddleware, updateLastLogin);
 
 // Availability Routes
-router.get('/:employeeId/availabilities', authMiddleware, getAvailabilities);
-router.put('/:employeeId/availabilities', authMiddleware, updateAvailabilities);
+router.get('/:employeeId/availabilities', validateEmployeeId, handleValidationErrors, authMiddleware, getAvailabilities);
+router.put('/:employeeId/availabilities', validateEmployeeId, validateAvailabilities, handleValidationErrors, authMiddleware, updateAvailabilities);
 
 export default router;

backend/src/routes/scheduledShifts.ts

@@ -1,4 +1,3 @@
-// backend/src/routes/scheduledShifts.ts
 import express from 'express';
 import { authMiddleware, requireRole } from '../middleware/auth.js';
 import { 
@@ -8,23 +7,21 @@ import {
   getScheduledShiftsFromPlan,
   updateScheduledShift
 } from '../controllers/shiftPlanController.js';
+import { 
+  validateId, 
+  validatePlanId, 
+  validateScheduledShiftUpdate, 
+  handleValidationErrors 
+} from '../middleware/validation.js';
 
 const router = express.Router();
 
 router.use(authMiddleware);
 
-
-router.post('/:id/generate-shifts', requireRole(['admin', 'maintenance']), generateScheduledShiftsForPlan);
-
-router.post('/:id/regenerate-shifts', requireRole(['admin', 'maintenance']), regenerateScheduledShifts);
-
-// GET all scheduled shifts for a plan
-router.get('/plan/:planId', authMiddleware, getScheduledShiftsFromPlan);
-
-// GET specific scheduled shift
-router.get('/:id', authMiddleware, getScheduledShift);
-
-// UPDATE scheduled shift
-router.put('/:id', authMiddleware, updateScheduledShift);
+router.post('/:id/generate-shifts', validateId, handleValidationErrors, requireRole(['admin', 'maintenance']), generateScheduledShiftsForPlan);
+router.post('/:id/regenerate-shifts', validateId, handleValidationErrors, requireRole(['admin', 'maintenance']), regenerateScheduledShifts);
+router.get('/plan/:planId', validatePlanId, handleValidationErrors, getScheduledShiftsFromPlan);
+router.get('/:id', validateId, handleValidationErrors, getScheduledShift);
+router.put('/:id', validateId, validateScheduledShiftUpdate, handleValidationErrors, updateScheduledShift);
 
 export default router;

backend/src/routes/scheduling.ts

@@ -1,9 +1,10 @@
 import express from 'express';
 import { SchedulingService } from '../services/SchedulingService.js';
+import { validateSchedulingRequest, handleValidationErrors } from '../middleware/validation.js';
 
 const router = express.Router();
 
-router.post('/generate-schedule', async (req, res) => {
+router.post('/generate-schedule', validateSchedulingRequest, handleValidationErrors, async (req: express.Request, res: express.Response) => {
   try {
     const { shiftPlan, employees, availabilities, constraints } = req.body;
     
@@ -14,18 +15,6 @@ router.post('/generate-schedule', async (req, res) => {
       constraintCount: constraints?.length
     });
 
-    // Validate required data
-    if (!shiftPlan || !employees || !availabilities) {
-      return res.status(400).json({ 
-        error: 'Missing required data',
-        details: {
-          shiftPlan: !!shiftPlan,
-          employees: !!employees,
-          availabilities: !!availabilities
-        }
-      });
-    }
-
     const scheduler = new SchedulingService();
     const result = await scheduler.generateOptimalSchedule({
       shiftPlan,

backend/src/routes/setup.ts

@@ -1,11 +1,10 @@
-// backend/src/routes/setup.ts
 import express from 'express';
-import bcrypt from 'bcryptjs';
 import { checkSetupStatus, setupAdmin } from '../controllers/setupController.js';
+import { validateSetupAdmin, handleValidationErrors } from '../middleware/validation.js';
 
 const router = express.Router();
 
 router.get('/status', checkSetupStatus);
-router.post('/admin', setupAdmin);
+router.post('/admin', validateSetupAdmin, handleValidationErrors, setupAdmin);
 
 export default router;

backend/src/routes/shiftPlans.ts

@@ -1,4 +1,3 @@
-// backend/src/routes/shiftPlans.ts
 import express from 'express';
 import { authMiddleware, requireRole } from '../middleware/auth.js';
 import { 
@@ -10,32 +9,25 @@ import {
   createFromPreset,
   clearAssignments
 } from '../controllers/shiftPlanController.js';
+import { 
+  validateShiftPlan, 
+  validateShiftPlanUpdate, 
+  validateCreateFromPreset, 
+  handleValidationErrors, 
+  validateId 
+} from '../middleware/validation.js';
 
 const router = express.Router();
 
 router.use(authMiddleware);
 
 // Combined routes for both shift plans and templates
-
-// GET all shift plans (including templates)
-router.get('/' , authMiddleware, getShiftPlans);
-
-// GET specific shift plan or template
-router.get('/:id', authMiddleware, getShiftPlan);
-
-// POST create new shift plan
-router.post('/', requireRole(['admin', 'maintenance']), createShiftPlan);
-
-// POST create new plan from preset
-router.post('/from-preset', requireRole(['admin', 'maintenance']), createFromPreset);
-
-// PUT update shift plan or template
-router.put('/:id', requireRole(['admin', 'maintenance']), updateShiftPlan);
-
-// DELETE shift plan or template
-router.delete('/:id', requireRole(['admin', 'maintenance']), deleteShiftPlan);
-
-// POST clear assignments and reset to draft
-router.post('/:id/clear-assignments', requireRole(['admin', 'maintenance']), clearAssignments);
+router.get('/', getShiftPlans);
+router.get('/:id', validateId, handleValidationErrors, getShiftPlan);
+router.post('/', validateShiftPlan, handleValidationErrors, requireRole(['admin', 'maintenance']), createShiftPlan);
+router.post('/from-preset', validateCreateFromPreset, handleValidationErrors, requireRole(['admin', 'maintenance']), createFromPreset);
+router.put('/:id', validateId, validateShiftPlanUpdate, handleValidationErrors, requireRole(['admin', 'maintenance']), updateShiftPlan);
+router.delete('/:id', validateId, handleValidationErrors, requireRole(['admin', 'maintenance']), deleteShiftPlan);
+router.post('/:id/clear-assignments', validateId, handleValidationErrors, requireRole(['admin', 'maintenance']), clearAssignments);
 
 export default router;

backend/src/scripts/applyMigration.ts

@@ -53,7 +53,7 @@ async function markMigrationAsApplied(migrationName: string) {
   );
 }
 
-// UPDATED: Function to handle schema changes for the new employee type system
+// Function to handle schema changes for the new employee type system
 async function applySchemaUpdates() {
   console.log('🔄 Applying schema updates for new employee type system...');
   
@@ -80,7 +80,7 @@ async function applySchemaUpdates() {
       PRAGMA table_info(employees)
     `);
     
-    // FIXED: Check for employee_type column (not roles column)
+    // Check for employee_type column (not roles column)
     const hasEmployeeType = employeesTableInfo.some((col: TableColumnInfo) => col.name === 'employee_type');
     const hasIsTrainee = employeesTableInfo.some((col: TableColumnInfo) => col.name === 'is_trainee');
     

backend/src/scripts/initializeDatabase.ts

@@ -65,7 +65,7 @@ export async function initializeDatabase(): Promise<void> {
 
       console.log('Existing tables found:', existingTables.map(t => t.name).join(', ') || 'none');
 
-      // UPDATED: Drop tables in correct dependency order for new schema
+      // Drop tables in correct dependency order for new schema
       const tablesToDrop = [
         'employee_availability',
         'shift_assignments',
@@ -95,16 +95,40 @@ export async function initializeDatabase(): Promise<void> {
       // Continue with schema creation even if table dropping fails
     }
 
-    // Execute schema creation in a transaction
-    await db.run('BEGIN EXCLUSIVE TRANSACTION');
-    
-    // Execute each statement separately for better error reporting
-    const statements = schema
+    // NEU: PRAGMA-Anweisungen außerhalb der Transaktion ausführen
+    console.log('Executing PRAGMA statements outside transaction...');
+    const pragmaStatements = schema
       .split(';')
       .map(stmt => stmt.trim())
       .filter(stmt => stmt.length > 0)
+      .filter(stmt => stmt.toUpperCase().startsWith('PRAGMA'))
+      .map(stmt => {
+        return stmt.split('\n')
+          .filter(line => !line.trim().startsWith('--'))
+          .join('\n')
+          .trim();
+      });
+
+    for (const statement of pragmaStatements) {
+      try {
+        console.log('Executing PRAGMA:', statement);
+        await db.run(statement);
+      } catch (error) {
+        console.warn('PRAGMA statement might have failed:', statement, error);
+        // Continue even if PRAGMA fails
+      }
+    }
+
+    // Schema-Erstellung in Transaktion
+    await db.run('BEGIN EXCLUSIVE TRANSACTION');
+
+    // Nur die CREATE TABLE und andere Anweisungen (ohne PRAGMA)
+    const schemaStatements = schema
+      .split(';')
+      .map(stmt => stmt.trim())
+      .filter(stmt => stmt.length > 0)
+      .filter(stmt => !stmt.toUpperCase().startsWith('PRAGMA'))
       .map(stmt => {
-        // Remove any single-line comments
         return stmt.split('\n')
           .filter(line => !line.trim().startsWith('--'))
           .join('\n')
@@ -112,7 +136,7 @@ export async function initializeDatabase(): Promise<void> {
       })
       .filter(stmt => stmt.length > 0);
 
-    for (const statement of statements) {
+    for (const statement of schemaStatements) {
       try {
         console.log('Executing statement:', statement.substring(0, 50) + '...');
         await db.run(statement);
@@ -124,7 +148,7 @@ export async function initializeDatabase(): Promise<void> {
       }
     }
 
-    // UPDATED: Insert default data in correct order
+    // Insert default data in correct order
     try {
       console.log('Inserting default employee types...');
       await db.run(`INSERT OR IGNORE INTO employee_types (type, category, has_contract_type) VALUES ('manager', 'internal', 1)`);

backend/src/scripts/verify-python.js

@@ -1,5 +1,4 @@
 import { spawn } from 'child_process';
-import path from 'path';
 
 export function runPythonScript(scriptPath, args = []) {
   return new Promise((resolve, reject) => {

backend/src/server.ts

@@ -4,6 +4,8 @@ import path from 'path';
 import { fileURLToPath } from 'url';
 import { initializeDatabase } from './scripts/initializeDatabase.js';
 import fs from 'fs';
+import helmet from 'helmet';
+import type { ViteDevServer } from 'vite';
 
 // Route imports
 import authRoutes from './routes/auth.js';
@@ -12,105 +14,313 @@ import shiftPlanRoutes from './routes/shiftPlans.js';
 import setupRoutes from './routes/setup.js';
 import scheduledShifts from './routes/scheduledShifts.js';
 import schedulingRoutes from './routes/scheduling.js';
+import { 
+  apiLimiter, 
+  authLimiter, 
+  expensiveEndpointLimiter
+} from './middleware/rateLimit.js';
+import { ipSecurityCheck as authIpCheck } from './middleware/auth.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
 
 const app = express();
 const PORT = 3002;
+const isDevelopment = process.env.NODE_ENV === 'development';
+
+app.use(authIpCheck);
+
+let vite: ViteDevServer | undefined;
+
+if (isDevelopment) {
+  // Dynamically import and setup Vite middleware
+  const setupViteDevServer = async () => {
+    try {
+      const { createServer } = await import('vite');
+      vite = await createServer({
+        server: { middlewareMode: true },
+        appType: 'spa'
+      });
+      app.use(vite.middlewares);
+      console.log('🔧 Vite dev server integrated with Express');
+    } catch (error) {
+      console.warn('⚠️ Vite integration failed, using static files:', error);
+    }
+  };
+  setupViteDevServer();
+}
+
+const configureStaticFiles = () => {
+  const staticConfig = {
+    maxAge: '1y',
+    etag: false,
+    immutable: true,
+    index: false
+  };
+
+  // Serve frontend build
+  const frontendPath = '/app/frontend-build';
+  if (fs.existsSync(frontendPath)) {
+    console.log('✅ Serving frontend from:', frontendPath);
+    app.use(express.static(frontendPath, staticConfig));
+  }
+
+  // Serve premium assets if available
+  const premiumPath = '/app/premium-dist';
+  if (fs.existsSync(premiumPath)) {
+    console.log('✅ Serving premium assets from:', premiumPath);
+    app.use('/premium-assets', express.static(premiumPath, staticConfig));
+  }
+};
+
+// Security configuration
+if (process.env.NODE_ENV === 'production') {
+  console.info('Checking for JWT_SECRET');
+  const JWT_SECRET = process.env.JWT_SECRET;
+  if (!JWT_SECRET || JWT_SECRET === 'your-secret-key-please-change') {
+    console.error('❌ Fatal: JWT_SECRET not set or using default value');
+    process.exit(1);
+  }
+}
+
+const configureTrustProxy = (): string | string[] | boolean | number => {
+  const trustedProxyIps = process.env.TRUSTED_PROXY_IPS;
+  const trustProxyEnabled = process.env.TRUST_PROXY_ENABLED !== 'false';
+
+  // If explicitly disabled
+  if (!trustProxyEnabled) {
+    console.log('🔒 Trust proxy: Disabled');
+    return false;
+  }
+
+  // If specific IPs are provided via environment variable
+  if (trustedProxyIps) {
+    console.log('🔒 Trust proxy: Using configured IPs:', trustedProxyIps);
+    
+    // Handle comma-separated list of IPs/CIDR ranges
+    if (trustedProxyIps.includes(',')) {
+      return trustedProxyIps.split(',').map(ip => ip.trim());
+    }
+    
+    // Handle single IP/CIDR
+    return trustedProxyIps.trim();
+  }
+
+  // Default behavior for reverse proxy setup
+  console.log('🔒 Trust proxy: Using reverse proxy defaults (trust all)');
+  return true; // Trust all proxies when behind nginx
+};
+
+app.set('trust proxy', configureTrustProxy());
+
+app.use((req, res, next) => {
+  const protocol = req.headers['x-forwarded-proto'] || req.protocol;
+  const isHttps = protocol === 'https';
+  
+  // Add security warning for HTTP requests
+  if (!isHttps && process.env.NODE_ENV === 'production') {
+    res.setHeader('X-Security-Warning', 'This application is being accessed over HTTP. For secure communication, please use HTTPS.');
+    
+    // Log HTTP access in production
+    console.warn(`⚠️  HTTP access detected: ${req.method} ${req.path} from ${req.ip}`);
+  }
+  
+  next();
+});
+
+// Security headers
+app.use(helmet({
+  contentSecurityPolicy: {
+    directives: {
+      defaultSrc: ["'self'"],
+      scriptSrc: ["'self'", "'unsafe-inline'"],
+      styleSrc: ["'self'", "'unsafe-inline'"],
+      imgSrc: ["'self'", "data:", "https:"],
+      connectSrc: ["'self'"],
+      fontSrc: ["'self'"],
+      objectSrc: ["'none'"],
+      mediaSrc: ["'self'"],
+      frameSrc: ["'none'"],
+      upgradeInsecureRequests: process.env.FORCE_HTTPS === 'true' ? [] : null
+    },
+  },
+  hsts: {
+    maxAge: 31536000,
+    includeSubDomains: true,
+    preload: true
+  }, // Enable HSTS for HTTPS
+  crossOriginEmbedderPolicy: false
+}));
+
+// Additional security headers
+app.use((req, res, next) => {
+  res.setHeader('X-Content-Type-Options', 'nosniff');
+  res.setHeader('X-Frame-Options', 'DENY');
+  res.setHeader('X-XSS-Protection', '1; mode=block');
+  next();
+});
 
 // Middleware
 app.use(express.json());
 
+// Rate limiting - weniger restriktiv in Development
+if (process.env.NODE_ENV === 'production') {
+  console.log('🔒 Applying production rate limiting');
+  app.use('/api/', apiLimiter);
+} else {
+  console.log('🔧 Development: Relaxed rate limiting applied');
+  // In development, you might want to be more permissive
+  app.use('/api/', apiLimiter);
+}
+
 // API Routes
 app.use('/api/setup', setupRoutes);
-app.use('/api/auth', authRoutes);
+app.use('/api/auth', authLimiter, authRoutes);
 app.use('/api/employees', employeeRoutes);
 app.use('/api/shift-plans', shiftPlanRoutes);
 app.use('/api/scheduled-shifts', scheduledShifts);
-app.use('/api/scheduling', schedulingRoutes);
+app.use('/api/scheduling', expensiveEndpointLimiter, schedulingRoutes);
 
 // Health route
-app.get('/api/health', (req: any, res: any) => {
+app.get('/api/health', (req: express.Request, res: express.Response) => {
   res.json({
     status: 'OK',
     message: 'Backend läuft!',
-    timestamp: new Date().toISOString()
+    timestamp: new Date().toISOString(),
+    mode: process.env.NODE_ENV || 'development'
   });
 });
 
-// 🆕 STATIC FILE SERVING FÜR FRONTEND
-const frontendBuildPath = path.join(__dirname, '../frontend-build');
-console.log('📁 Frontend build path:', frontendBuildPath);
+// 🆕 IMPROVED STATIC FILE SERVING
+const findFrontendBuildPath = (): string | null => {
+  const possiblePaths = [
+    // Production path (Docker)
+    '/app/frontend-build',
+    // Development paths
+    path.resolve(__dirname, '../../frontend/dist'),
+    path.resolve(__dirname, '../../frontend-build'),
+    path.resolve(process.cwd(), '../frontend/dist'),
+    path.resolve(process.cwd(), 'frontend-build'),
+  ];
 
-// Überprüfe ob das Verzeichnis existiert
-if (fs.existsSync(frontendBuildPath)) {
-  console.log('✅ Frontend build directory exists');
-  const files = fs.readdirSync(frontendBuildPath);
-  console.log('📄 Files in frontend-build:', files);
+  for (const testPath of possiblePaths) {
+    try {
+      if (fs.existsSync(testPath)) {
+        const indexPath = path.join(testPath, 'index.html');
+        if (fs.existsSync(indexPath)) {
+          console.log('✅ Found frontend build at:', testPath);
+          return testPath;
+        }
+      }
+    } catch (error) {
+      // Silent catch - just try next path
+    }
+  }
+  return null;
+};
 
-  // Serviere statische Dateien
+const frontendBuildPath = findFrontendBuildPath();
+configureStaticFiles();
+
+if (frontendBuildPath) {
   app.use(express.static(frontendBuildPath));
-  
   console.log('✅ Static file serving configured');
 } else {
-  console.log('❌ Frontend build directory NOT FOUND:', frontendBuildPath);
+  console.log(isDevelopment ?
+    '🔧 Development: Frontend served by Vite dev server (localhost:3003)' :
+    '❌ Production: No frontend build found'
+  );
+}
+
+// Root route
+app.get('/', async (req, res) => {
+  // In development with Vite middleware
+  if (vite) {
+    try {
+      const template = fs.readFileSync(
+        path.resolve(__dirname, '../../frontend/index.html'),
+        'utf-8'
+      );
+      const html = await vite.transformIndexHtml(req.url, template);
+      res.send(html);
+    } catch (error) {
+      res.status(500).send('Vite dev server error');
+    }
+    return;
+  }
+
+  // Fallback to static file serving
+  if (!frontendBuildPath) {
+    return res.status(500).send('Frontend not available');
   }
 
-app.get('/', (req, res) => {
   const indexPath = path.join(frontendBuildPath, 'index.html');
-  console.log('📄 Serving index.html from:', indexPath);
-  
-  if (fs.existsSync(indexPath)) {
   res.sendFile(indexPath);
-  } else {
-    console.error('❌ index.html not found at:', indexPath);
-    res.status(404).send('Frontend not found - index.html missing');
-  }
 });
 
-app.get('*', (req, res) => {
-  // Ignoriere API Routes
+// Client-side routing fallback
+app.get('*', (req, res, next) => {
+  // Skip API routes
   if (req.path.startsWith('/api/')) {
-    return res.status(404).json({ error: 'API endpoint not found' });
+    return next();
   }
 
-  const indexPath = path.join(frontendBuildPath, 'index.html');
-  console.log('🔄 Client-side routing for:', req.path, '-> index.html');
+  // Skip file extensions (assets)
+  if (req.path.match(/\.[a-z0-9]+$/i)) {
+    return next();
+  }
+
+  // Serve React app for all other routes
+  const frontendPath = '/app/frontend-build';
+  const indexPath = path.join(frontendPath, 'index.html');
   
   if (fs.existsSync(indexPath)) {
     res.sendFile(indexPath);
   } else {
-    console.error('❌ index.html not found for client-side routing');
-    res.status(404).json({ error: 'Frontend application not found' });
+    res.status(404).send('Frontend not available');
   }
 });
 
-// Error handling middleware
+// Error handling
 app.use((err: any, req: express.Request, res: express.Response, next: express.NextFunction) => {
-  console.error('Unhandled error:', err);
-  res.status(500).json({ error: 'Internal server error' });
+  console.error('Error:', err);
+
+  if (process.env.NODE_ENV === 'production') {
+    res.status(500).json({
+      error: 'Internal server error',
+      message: 'Something went wrong'
+    });
+  } else {
+    res.status(500).json({
+      error: 'Internal server error',
+      message: err.message,
+      stack: err.stack
+    });
+  }
+});
+
+// 404 handling
+app.use('*', (req, res) => {
+  res.status(404).json({ error: 'Endpoint not found' });
 });
 
 // Initialize the application
 const initializeApp = async () => {
   try {
-    // Initialize database with base schema
     await initializeDatabase();
-    
-    // Apply any pending migrations
     const { applyMigration } = await import('./scripts/applyMigration.js');
     await applyMigration();
 
-    // Start server only after successful initialization
     app.listen(PORT, () => {
       console.log('🎉 APPLICATION STARTED SUCCESSFULLY!');
       console.log(`📍 Port: ${PORT}`);
+      console.log(`📍 Mode: ${process.env.NODE_ENV || 'development'}`);
+      if (frontendBuildPath) {
         console.log(`📍 Frontend: http://localhost:${PORT}`);
+      } else if (isDevelopment) {
+        console.log(`📍 Frontend (Vite): http://localhost:3003`);
+      }
       console.log(`📍 API: http://localhost:${PORT}/api`);
-      console.log('');
-      console.log(`🔧 Setup: http://localhost:${PORT}/api/setup/status`);
-      console.log('📝 Create your admin account on first launch');
     });
   } catch (error) {
     console.error('❌ Error during initialization:', error);
@@ -118,5 +328,4 @@ const initializeApp = async () => {
   }
 };
 
-// Start the application
 initializeApp();

backend/src/services/SchedulingService.ts

@@ -2,8 +2,7 @@
 import { Worker } from 'worker_threads';
 import path from 'path';
 import { fileURLToPath } from 'url';
-import { Employee, EmployeeAvailability } from '../models/Employee.js';
-import { ShiftPlan, ScheduledShift } from '../models/ShiftPlan.js';
+import { ShiftPlan } from '../models/ShiftPlan.js';
 import { ScheduleRequest, ScheduleResult, Availability, Constraint } from '../models/scheduling.js';
 
 const __filename = fileURLToPath(import.meta.url);

backend/src/workers/scheduler-worker.ts

@@ -2,8 +2,8 @@
 import { parentPort, workerData } from 'worker_threads';
 import { CPModel, CPSolver } from './cp-sat-wrapper.js';
 import { ShiftPlan, Shift } from '../models/ShiftPlan.js';
-import { Employee, EmployeeAvailability } from '../models/Employee.js';
-import { Availability, Constraint, Violation, SolverOptions, Solution, Assignment } from '../models/scheduling.js';
+import { Employee } from '../models/Employee.js';
+import { Availability, Constraint } from '../models/scheduling.js';
 
 interface WorkerData {
   shiftPlan: ShiftPlan;

backend/tsconfig.json

@@ -1,19 +1,22 @@
-// backend/tsconfig.json
 {
   "compilerOptions": {
     "target": "ES2022",
     "module": "NodeNext",
     "moduleResolution": "NodeNext",
-    "allowSyntheticDefaultImports": true,
-    "esModuleInterop": true,
-    "allowJs": true,
     "outDir": "./dist",
     "rootDir": "./src",
     "strict": true,
+    "esModuleInterop": true,
     "skipLibCheck": true,
     "forceConsistentCasingInFileNames": true,
-    "resolveJsonModule": true
+    "resolveJsonModule": true,
+    "allowSyntheticDefaultImports": true
   },
-  "include": ["src/**/*"],
-  "exclude": ["node_modules", "dist"]
+  "include": [
+    "src/**/*"
+  ],
+  "exclude": [
+    "node_modules",
+    "dist"
+  ]
 }

docker-compose.yml

@@ -1,26 +1,27 @@
 version: '3.8'
 
 services:
-  schichtplan:
-    build: 
-      context: .
-      dockerfile: backend/Dockerfile
-    ports:
-      - "3001:3001"
-      - "3000:3000"
+  schichtplaner:
+    container_name: schichtplaner
+    image: ghcr.io/donpat1to/schichtenplaner:v1.0.0
     environment:
       - NODE_ENV=production
-      - DATABASE_URL=file:./prod.db
-      - JWT_SECRET=your-production-secret-key-change-this
-      - PYTHON_PATH=/usr/bin/python3
+      - JWT_SECRET=${JWT_SECRET}
+      - TRUST_PROXY_ENABLED=true
+      - TRUSTED_PROXY_IPS=nginx-proxy,172.0.0.0/8,10.0.0.0/8,192.168.0.0/16
+      - FORCE_HTTPS=${FORCE_HTTPS:-false}
+    networks:
+      - app-network
     volumes:
       - app_data:/app/data
     restart: unless-stopped
     healthcheck:
-      test: ["CMD", "curl", "-f", "http://localhost:3001/health"]
+      test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://localhost:3002/api/health"]
       interval: 30s
       timeout: 10s
       retries: 3
+    expose:
+      - "3002"
 
 volumes:
   app_data:

docker-init.sh

@@ -0,0 +1,55 @@
+#!/bin/bash
+set -e
+
+echo "🚀 Container Initialisierung gestartet..."
+
+generate_secret() {
+    length=$1
+    tr -dc 'A-Za-z0-9!@#$%^&*()_+-=' < /dev/urandom | head -c $length
+}
+
+# Create .env if it doesn't exist
+if [ ! -f /app/.env ]; then
+    echo "📝 Erstelle .env Datei..."
+    
+    if [ -z "$JWT_SECRET" ] || [ "$JWT_SECRET" = "your-secret-key-please-change" ]; then
+        export JWT_SECRET=$(generate_secret 64)
+        echo "🔑 Automatisch sicheres JWT Secret generiert"
+    else
+        echo "🔑 Verwende vorhandenes JWT Secret aus Umgebungsvariable"
+    fi
+    
+    # Create .env with all proxy settings
+    cat > /app/.env << EOF
+NODE_ENV=production
+JWT_SECRET=${JWT_SECRET}
+TRUST_PROXY_ENABLED=${TRUST_PROXY_ENABLED:-true}
+TRUSTED_PROXY_IPS=${TRUSTED_PROXY_IPS:-172.0.0.0/8,10.0.0.0/8,192.168.0.0/16}
+HOSTNAME=${HOSTNAME:-localhost}
+EOF
+    
+    echo "✅ .env Datei erstellt"
+else
+    echo "ℹ️  .env Datei existiert bereits"
+    
+    # Update JWT_SECRET if provided
+    if [ -n "$JWT_SECRET" ] && [ "$JWT_SECRET" != "your-secret-key-please-change" ]; then
+        echo "🔑 Aktualisiere JWT Secret in .env Datei"
+        sed -i "s/^JWT_SECRET=.*/JWT_SECRET=$JWT_SECRET/" /app/.env
+    fi
+fi
+
+# Validate JWT_SECRET
+if grep -q "JWT_SECRET=your-secret-key-please-change" /app/.env; then
+    echo "❌ FEHLER: Standard JWT Secret in .env gefunden!"
+    echo "❌ Bitte setzen Sie JWT_SECRET Umgebungsvariable"
+    exit 1
+fi
+
+chmod 600 /app/.env
+
+echo "🔧 Proxy Configuration:"
+echo "   - TRUST_PROXY_ENABLED: ${TRUST_PROXY_ENABLED:-true}"
+echo "   - TRUSTED_PROXY_IPS: ${TRUSTED_PROXY_IPS:-172.0.0.0/8,10.0.0.0/8,192.168.0.0/16}"
+echo "🔧 Starte Anwendung..."
+exec "$@"

ecosystem.config.cjs

@@ -1,18 +1,17 @@
 // ecosystem.config.cjs
 module.exports = {
-  apps: [
-    {
-      name: 'schichtplaner',
+  apps: [{
+    name: 'schichtplan-app',
     script: './dist/server.js',
     instances: 1,
-      exec_mode: 'fork',
     env: {
       NODE_ENV: 'production',
-        PORT: 3002
+      PORT: 3002,
+      FRONTEND_BUILD_PATH: './frontend-build'
     },
-      error_file: './logs/app-err.log',
-      out_file: './logs/app-out.log',
+    error_file: './logs/err.log',
+    out_file: './logs/out.log',
+    log_file: './logs/combined.log',
     time: true
-    }
-  ]
+  }]
 };

frontend/.env.development

@@ -1,4 +0,0 @@
-# frontend/.env.development
-BROWSER=none
-FAST_REFRESH=true
-DANGEROUSLY_DISABLE_HOST_CHECK=true

frontend/index.html

@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Shift Planning App</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>

frontend/package.json

@@ -2,49 +2,34 @@
   "name": "frontend",
   "version": "0.1.0",
   "private": true,
-  "proxy": "http://localhost:3002",
+  "type": "module",
   "dependencies": {
-    "@testing-library/dom": "^10.4.1",
-    "@testing-library/jest-dom": "^6.9.1",
-    "@testing-library/react": "^16.3.0",
-    "@testing-library/user-event": "^13.5.0",
-    "@types/jest": "^27.5.2",
-    "@types/node": "^16.18.126",
-    "@types/react": "^19.2.2",
-    "@types/react-dom": "^19.2.1",
-    "@types/react-router-dom": "^5.3.3",
-    "react": "^19.2.0",
-    "react-dom": "^19.2.0",
-    "react-router-dom": "^7.9.3",
-    "typescript": "^4.9.5",
-    "web-vitals": "^2.1.4"
-  },
-  "scripts": {
-    "start": "react-scripts start",
-    "build": "react-scripts build",
-    "test": "react-scripts test",
-    "eject": "react-scripts eject"
-  },
-  "eslintConfig": {
-    "extends": [
-      "react-app",
-      "react-app/jest"
-    ]
-  },
-  "browserslist": {
-    "production": [
-      ">0.2%",
-      "not dead",
-      "not op_mini all"
-    ],
-    "development": [
-      "last 1 chrome version",
-      "last 1 firefox version",
-      "last 1 safari version"
-    ]
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0",
+    "react-router-dom": "^6.28.0",
+    "date-fns": "4.1.0"
   },
   "devDependencies": {
-    "http-proxy-middleware": "^3.0.5",
-    "react-scripts": "^5.0.1"
+    "@types/node": "20.19.23",
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
+    "@types/react-router-dom": "^5.3.3",
+    "@vitejs/plugin-react": "^4.3.3",
+    "@types/jest": "30.0.0",
+    "@testing-library/react": "10.4.1",
+    "@testing-library/jest-dom": "6.9.1",
+    "@testing-library/user-event": "14.6.1",
+    "@storybook/react": "10.0.1",
+    "typescript": "^5.7.3",
+    "vite": "^6.0.7",
+    "esbuild": "^0.21.0",
+    "terser": "5.44.0",
+    "babel-plugin-transform-remove-console": "6.9.4",
+    "framer-motion": "12.23.24"
+  },
+  "scripts": {
+    "dev": "vite dev",
+    "build": "tsc && vite build",
+    "preview": "vite preview"
   }
 }

frontend/public/manifest.json

@@ -1,6 +1,6 @@
 {
-  "short_name": "React App",
-  "name": "Create React App Sample",
+  "short_name": "SP",
+  "name": "schichtenplaner",
   "icons": [
     {
       "src": "favicon.ico",

frontend/src/App.test.tsx

@@ -1,9 +0,0 @@
-import React from 'react';
-import { render, screen } from '@testing-library/react';
-import App from './App';
-
-test('renders learn react link', () => {
-  render(<App />);
-  const linkElement = screen.getByText(/learn react/i);
-  expect(linkElement).toBeInTheDocument();
-});

frontend/src/App.tsx

@@ -1,4 +1,4 @@
-// frontend/src/App.tsx - KORRIGIERT MIT LAYOUT
+// src/App.tsx
 import React from 'react';
 import { BrowserRouter as Router, Routes, Route } from 'react-router-dom';
 import { AuthProvider, useAuth } from './contexts/AuthContext';
@@ -15,6 +15,40 @@ import EmployeeManagement from './pages/Employees/EmployeeManagement';
 import Settings from './pages/Settings/Settings';
 import Help from './pages/Help/Help';
 import Setup from './pages/Setup/Setup';
+import ErrorBoundary from './components/ErrorBoundary/ErrorBoundary';
+import SecurityWarning from './components/SecurityWarning/SecurityWarning';
+
+// Free Footer Link Pages (always available)
+import FAQ from './components/Layout/FooterLinks/FAQ/FAQ';
+import About from './components/Layout/FooterLinks/About/About';
+import Features from './components/Layout/FooterLinks/Features/Features';
+import { CommunityContact, CommunityLegalPage } from './components/Layout/FooterLinks/CommunityLinks/communityLinks';
+
+// Vite environment variables (use import.meta.env instead of process.env)
+const ENABLE_PRO = import.meta.env.ENABLE_PRO === 'true';
+
+// Conditional Premium Components
+let PremiumContact: React.FC = CommunityContact;
+let PremiumPrivacy: React.FC = () => <CommunityLegalPage title="Datenschutz" />;
+let PremiumImprint: React.FC = () => <CommunityLegalPage title="Impressum" />;
+let PremiumTerms: React.FC = () => <CommunityLegalPage title="AGB" />;
+
+// Load premium components only when ENABLE_PRO is true
+if (ENABLE_PRO) {
+  try {
+    // Use require with type assertions to avoid dynamic import issues
+    const premiumModule = require('@premium-frontend/components/FooterLinks');
+
+    if (premiumModule.Contact) PremiumContact = premiumModule.Contact;
+    if (premiumModule.Privacy) PremiumPrivacy = premiumModule.Privacy;
+    if (premiumModule.Imprint) PremiumImprint = premiumModule.Imprint;
+    if (premiumModule.Terms) PremiumTerms = premiumModule.Terms;
+    
+    console.log('✅ Premium components loaded successfully');
+  } catch (error) {
+    console.warn('⚠️ Premium components not available, using community fallbacks:', error);
+  }
+}
 
 // Protected Route Component
 const ProtectedRoute: React.FC<{ children: React.ReactNode; roles?: string[] }> = ({ 
@@ -49,11 +83,27 @@ const ProtectedRoute: React.FC<{ children: React.ReactNode; roles?: string[] }>
   return <Layout>{children}</Layout>;
 };
 
+// Public Route Component (without Layout for footer pages)
+const PublicRoute: React.FC<{ children: React.ReactNode }> = ({ children }) => {
+  const { user, loading } = useAuth();
+
+  if (loading) {
+    return (
+      <div style={{ textAlign: 'center', padding: '40px' }}>
+        <div>⏳ Lade Anwendung...</div>
+      </div>
+    );
+  }
+
+  return user ? <Layout>{children}</Layout> : <>{children}</>;
+};
+
 // Main App Content
 const AppContent: React.FC = () => {
   const { loading, needsSetup, user } = useAuth();
 
   console.log('🏠 AppContent rendering - loading:', loading, 'needsSetup:', needsSetup, 'user:', user);
+  console.log('🎯 Premium features enabled:', ENABLE_PRO);
 
   // Während des Ladens
   if (loading) {
@@ -80,66 +130,49 @@ const AppContent: React.FC = () => {
   console.log('✅ Showing protected routes for user:', user.email);
   return (
     <Routes>
-      <Route path="/" element={
-        <ProtectedRoute>
-          <Dashboard />
-        </ProtectedRoute>
-      } />
-      <Route path="/shift-plans" element={
-        <ProtectedRoute>
-          <ShiftPlanList />
-        </ProtectedRoute>
-      } />
-      <Route path="/shift-plans/new" element={
-        <ProtectedRoute roles={['admin', 'maintenance']}>
-          <ShiftPlanCreate />
-        </ProtectedRoute>
-      } />
-      <Route path="/shift-plans/:id/edit" element={
-        <ProtectedRoute roles={['admin', 'maintenance']}>
-          <ShiftPlanEdit />
-        </ProtectedRoute>
-      } />
-      <Route path="/shift-plans/:id" element={
-        <ProtectedRoute>
-          <ShiftPlanView />
-        </ProtectedRoute>
-      } />
-      <Route path="/employees" element={
-        <ProtectedRoute roles={['admin', 'maintenance']}>
-          <EmployeeManagement />
-        </ProtectedRoute>
-      } />
-      <Route path="/settings" element={
-        <ProtectedRoute>
-          <Settings />
-        </ProtectedRoute>
-      } />
-      <Route path="/help" element={
-        <ProtectedRoute>
-          <Help />
-        </ProtectedRoute>
-      } />
+      {/* Protected Routes (require login) */}
+      <Route path="/" element={<ProtectedRoute><Dashboard /></ProtectedRoute>} />
+      <Route path="/shift-plans" element={<ProtectedRoute><ShiftPlanList /></ProtectedRoute>} />
+      <Route path="/shift-plans/new" element={<ProtectedRoute roles={['admin', 'maintenance']}><ShiftPlanCreate /></ProtectedRoute>} />
+      <Route path="/shift-plans/:id/edit" element={<ProtectedRoute roles={['admin', 'maintenance']}><ShiftPlanEdit /></ProtectedRoute>} />
+      <Route path="/shift-plans/:id" element={<ProtectedRoute><ShiftPlanView /></ProtectedRoute>} />
+      <Route path="/employees" element={<ProtectedRoute roles={['admin', 'maintenance']}><EmployeeManagement /></ProtectedRoute>} />
+      <Route path="/settings" element={<ProtectedRoute><Settings /></ProtectedRoute>} />
+      <Route path="/help" element={<ProtectedRoute><Help /></ProtectedRoute>} />
+
+      {/* Public Footer Link Pages (always available) */}
+      <Route path="/faq" element={<PublicRoute><FAQ /></PublicRoute>} />
+      <Route path="/about" element={<PublicRoute><About /></PublicRoute>} />
+      <Route path="/features" element={<PublicRoute><Features /></PublicRoute>} />
+
+      {/* PREMIUM Footer Link Pages (conditionally available) */}
+      <Route path="/contact" element={<PublicRoute><PremiumContact /></PublicRoute>} />
+      <Route path="/privacy" element={<PublicRoute><PremiumPrivacy /></PublicRoute>} />
+      <Route path="/imprint" element={<PublicRoute><PremiumImprint /></PublicRoute>} />
+      <Route path="/terms" element={<PublicRoute><PremiumTerms /></PublicRoute>} />
+
+      {/* Auth Routes */}
       <Route path="/login" element={<Login />} />
-      <Route path="*" element={
-        <ProtectedRoute>
-          <Dashboard />
-        </ProtectedRoute>
-      } />
+      
+      {/* Catch-all Route */}
+      <Route path="*" element={<ProtectedRoute><Dashboard /></ProtectedRoute>} />
     </Routes>
   );
 };
 
 function App() {
   return (
+    <ErrorBoundary>
       <NotificationProvider>
         <AuthProvider>
           <Router>
+            <SecurityWarning />
             <NotificationContainer />
             <AppContent />
           </Router>
         </AuthProvider>
       </NotificationProvider>
+    </ErrorBoundary>
   );
 }
 

frontend/src/components/ErrorBoundary/ErrorBoundary.tsx

@@ -0,0 +1,101 @@
+// src/components/ErrorBoundary/ErrorBoundary.tsx
+import React from 'react';
+
+interface Props {
+  children: React.ReactNode;
+  fallback?: React.ReactNode;
+}
+
+interface State {
+  hasError: boolean;
+  error?: Error;
+}
+
+class ErrorBoundary extends React.Component<Props, State> {
+  constructor(props: Props) {
+    super(props);
+    this.state = { hasError: false };
+  }
+
+  static getDerivedStateFromError(error: Error): State {
+    return { hasError: true, error };
+  }
+
+  componentDidCatch(error: Error, errorInfo: React.ErrorInfo) {
+    console.error('🚨 Application Error:', error);
+    console.error('📋 Error Details:', errorInfo);
+    
+    // In production, send to your error reporting service
+    // logErrorToService(error, errorInfo);
+  }
+
+  render() {
+    if (this.state.hasError) {
+      // You can render any custom fallback UI
+      return this.props.fallback || (
+        <div style={{ 
+          padding: '40px', 
+          textAlign: 'center',
+          fontFamily: 'Arial, sans-serif'
+        }}>
+          <div style={{ fontSize: '48px', marginBottom: '20px' }}>⚠️</div>
+          <h2>Oops! Something went wrong</h2>
+          <p style={{ margin: '20px 0', color: '#666' }}>
+            We encountered an unexpected error. Please try refreshing the page.
+          </p>
+          <div style={{ marginTop: '30px' }}>
+            <button
+              onClick={() => window.location.reload()}
+              style={{
+                padding: '10px 20px',
+                backgroundColor: '#007bff',
+                color: 'white',
+                border: 'none',
+                borderRadius: '4px',
+                cursor: 'pointer',
+                marginRight: '10px'
+              }}
+            >
+              Refresh Page
+            </button>
+            <button
+              onClick={() => this.setState({ hasError: false })}
+              style={{
+                padding: '10px 20px',
+                backgroundColor: '#6c757d',
+                color: 'white',
+                border: 'none',
+                borderRadius: '4px',
+                cursor: 'pointer'
+              }}
+            >
+              Try Again
+            </button>
+          </div>
+          {process.env.NODE_ENV === 'development' && this.state.error && (
+            <details style={{ 
+              marginTop: '20px', 
+              textAlign: 'left',
+              background: '#f8f9fa',
+              padding: '15px',
+              borderRadius: '4px'
+            }}>
+              <summary>Error Details (Development)</summary>
+              <pre style={{ 
+                whiteSpace: 'pre-wrap',
+                fontSize: '12px',
+                color: '#dc3545'
+              }}>
+                {this.state.error.stack}
+              </pre>
+            </details>
+          )}
+        </div>
+      );
+    }
+
+    return this.props.children;
+  }
+}
+
+export default ErrorBoundary;

frontend/src/components/Layout/Footer.tsx

@@ -1,4 +1,4 @@
-// frontend/src/components/Layout/Footer.tsx - ELEGANT WHITE DESIGN
+// frontend/src/components/Layout/Footer.tsx
 import React from 'react';
 
 const Footer: React.FC = () => {
@@ -10,12 +10,12 @@ const Footer: React.FC = () => {
       borderTop: '1px solid rgba(251, 250, 246, 0.1)',
     },
     footerContent: {
-      maxWidth: '1200px',
+      maxWidth: '1500px',
       margin: '0 auto',
       padding: '3rem 2rem 2rem',
       display: 'grid',
-      gridTemplateColumns: 'repeat(auto-fit, minmax(250px, 1fr))',
-      gap: '3rem',
+      gridTemplateColumns: 'repeat(auto-fit, minmax(100px, 1fr))',
+      gap: '1rem',
     },
     footerSection: {
       display: 'flex',
@@ -182,20 +182,6 @@ const Footer: React.FC = () => {
           >
             Funktionen
           </a>
-          <a 
-            href="/pricing" 
-            style={styles.footerLink}
-            onMouseEnter={(e) => {
-              e.currentTarget.style.color = '#FBFAF6';
-              e.currentTarget.style.transform = 'translateX(4px)';
-            }}
-            onMouseLeave={(e) => {
-              e.currentTarget.style.color = 'rgba(251, 250, 246, 0.7)';
-              e.currentTarget.style.transform = 'translateX(0)';
-            }}
-          >
-            Preise
-          </a>
         </div>
       </div>
       

frontend/src/components/Layout/FooterLinks/About/About.tsx

@@ -0,0 +1,76 @@
+// frontend/src/components/Layout/FooterLinks/About/About.tsx
+import React from 'react';
+
+const About: React.FC = () => {
+  return (
+    <div style={{ padding: '40px 20px', maxWidth: '800px', margin: '0 auto' }}>
+      <h1>👨‍💻 Über uns</h1>
+      
+      <div style={{ 
+        backgroundColor: 'white', 
+        borderRadius: '12px', 
+        padding: '30px', 
+        marginTop: '20px',
+        boxShadow: '0 4px 6px rgba(0,0,0,0.1)',
+        border: '1px solid #e0e0e0',
+        lineHeight: 1.6
+      }}>
+        <h2 style={{ color: '#2c3e50' }}>Unser Team</h2>
+        
+        <div style={{ display: 'flex', alignItems: 'center', marginTop: '20px', padding: '20px', backgroundColor: '#f8f9fa', borderRadius: '8px' }}>
+          <div style={{ marginRight: '20px' }}>
+            <div style={{ 
+              width: '80px', 
+              height: '80px', 
+              backgroundColor: '#3498db', 
+              borderRadius: '50%',
+              display: 'flex',
+              alignItems: 'center',
+              justifyContent: 'center',
+              color: 'white',
+              fontSize: '2rem',
+              fontWeight: 'bold'
+            }}>
+              P
+            </div>
+          </div>
+          <div>
+            <h3 style={{ color: '#2c3e50', margin: '0 0 5px 0' }}>Patrick</h3>
+            <p style={{ color: '#6c757d', margin: '0 0 10px 0' }}>
+              Full-Stack Developer & Projektleiter
+            </p>
+            <p style={{ margin: 0, fontSize: '0.9rem' }}>
+              GitHub: <a href="https://github.com/donpat1to" style={{ color: '#3498db' }}>donpat1to</a><br/>
+              E-Mail: <a href="mailto:dev.patrick@inca-vikingo.de" style={{ color: '#3498db' }}>dev.patrick@inca-vikingo.de</a>
+            </p>
+          </div>
+        </div>
+        
+        <h3 style={{ color: '#3498db', marginTop: '30px' }}>🚀 Unsere Mission</h3>
+        <p>
+          Wir entwickeln intelligente Lösungen für die Personalplanung, 
+          die Zeit sparen und faire Schichtverteilung gewährleisten.
+        </p>
+        
+        <h3 style={{ color: '#3498db', marginTop: '25px' }}>💻 Technologie</h3>
+        <p>
+          Unser Stack umfasst moderne Technologien:
+        </p>
+        <ul>
+          <li>Frontend: React, TypeScript</li>
+          <li>Backend: Node.js, Express</li>
+          <li>Optimierung: Google OR-Tools CP-SAT</li>
+          <li>Datenbank: SQLite/PostgreSQL</li>
+        </ul>
+        
+        <h3 style={{ color: '#3498db', marginTop: '25px' }}>📈 Entwicklung</h3>
+        <p>
+          Schichtenplaner wird kontinuierlich weiterentwickelt und 
+          basiert auf Feedback unserer Nutzer.
+        </p>
+      </div>
+    </div>
+  );
+};
+
+export default About;

frontend/src/components/Layout/FooterLinks/CommunityLinks/communityLinks.tsx

@@ -0,0 +1,38 @@
+// frontend/src/components/Layout/FooterLinks/CommunityLinks/communityLinks.tsx
+import React from 'react';
+
+export const CommunityContact: React.FC = () => (
+  <div style={{ padding: '40px 20px', maxWidth: '800px', margin: '0 auto' }}>
+    <h1>📞 Kontakt</h1>
+    <div style={{ backgroundColor: 'white', borderRadius: '12px', padding: '30px', marginTop: '20px' }}>
+      <h2 style={{ color: '#2c3e50' }}>Community Edition</h2>
+      <p>Kontaktfunktionen sind in der Premium Edition verfügbar.</p>
+      <p>
+        <a href="/features" style={{ color: '#3498db' }}>
+          ➡️ Zu den Features
+        </a>
+      </p>
+    </div>
+  </div>
+);
+
+export const CommunityLegalPage: React.FC<{ title: string }> = ({ title }) => (
+  <div style={{ padding: '40px 20px', maxWidth: '800px', margin: '0 auto' }}>
+    <h1>📄 {title}</h1>
+    <div style={{ backgroundColor: 'white', borderRadius: '12px', padding: '30px', marginTop: '20px' }}>
+      <h2 style={{ color: '#2c3e50' }}>Community Edition</h2>
+      <p>Rechtliche Dokumentation ist in der Premium Edition verfügbar.</p>
+      <p>
+        <a href="/features" style={{ color: '#3498db' }}>
+          ➡️ Erfahren Sie mehr über Premium
+        </a>
+      </p>
+    </div>
+  </div>
+);
+
+// Optional: Barrel export für einfachere Imports
+export default {
+  CommunityContact,
+  CommunityLegalPage
+};

frontend/src/components/Layout/FooterLinks/FAQ/FAQ.tsx

@@ -0,0 +1,103 @@
+// frontend/src/components/Layout/FooterLinks/FAQ/FAQ.tsx
+import React, { useState } from 'react';
+
+const FAQ: React.FC = () => {
+  const [openItems, setOpenItems] = useState<number[]>([]);
+
+  const toggleItem = (index: number) => {
+    setOpenItems(prev => 
+      prev.includes(index) 
+        ? prev.filter(i => i !== index)
+        : [...prev, index]
+    );
+  };
+
+  const faqItems = [
+    {
+      question: "Wie funktioniert der Scheduling-Algorithmus?",
+      answer: "Unser System verwendet Google's OR-Tools CP-SAT Solver, um optimale Schichtzuweisungen basierend auf Verfügbarkeiten, Vertragstypen und Geschäftsregeln zu berechnen."
+    },
+    {
+      question: "Was bedeuten die Verfügbarkeits-Level 1, 2 und 3?",
+      answer: "Level 1: Bevorzugt (Mitarbeiter möchte diese Schicht), Level 2: Verfügbar (kann arbeiten), Level 3: Nicht verfügbar (kann nicht arbeiten)."
+    },
+    {
+      question: "Wie werden Vertragstypen berücksichtigt?",
+      answer: "Kleine Verträge: 1 Schicht pro Woche, Große Verträge: 2 Schichten pro Woche. Das System weist genau diese Anzahl zu."
+    },
+    {
+      question: "Kann ich manuelle Anpassungen vornehmen?",
+      answer: "Ja, nach dem automatischen Scheduling können Sie Zuordnungen manuell anpassen und optimieren."
+    },
+    {
+      question: "Was passiert bei unterbesetzten Schichten?",
+      answer: "Das System zeigt eine Warnung an und versucht, alternative Lösungen zu finden. In kritischen Fällen müssen manuelle Anpassungen vorgenommen werden."
+    },
+    {
+      question: "Wie lange dauert die Planungserstellung?",
+      answer: "Typischerweise maximal 105 Sekunden, abhängig von der Anzahl der Mitarbeiter und Schichten."
+    }
+  ];
+
+  return (
+    <div style={{ padding: '40px 20px', maxWidth: '800px', margin: '0 auto' }}>
+      <h1>❓ Häufige Fragen (FAQ)</h1>
+      
+      <div style={{ 
+        backgroundColor: 'white', 
+        borderRadius: '12px', 
+        marginTop: '20px',
+        boxShadow: '0 4px 6px rgba(0,0,0,0.1)',
+        border: '1px solid #e0e0e0'
+      }}>
+        {faqItems.map((item, index) => (
+          <div key={index} style={{ 
+            borderBottom: index < faqItems.length - 1 ? '1px solid #e0e0e0' : 'none',
+            padding: '20px 30px'
+          }}>
+            <div
+              onClick={() => toggleItem(index)}
+              style={{
+                cursor: 'pointer',
+                display: 'flex',
+                justifyContent: 'space-between',
+                alignItems: 'center'
+              }}
+            >
+              <h3 style={{ 
+                color: '#2c3e50', 
+                margin: 0,
+                fontSize: '1.1rem'
+              }}>
+                {item.question}
+              </h3>
+              <span style={{ 
+                fontSize: '1.5rem',
+                color: '#3498db',
+                transform: openItems.includes(index) ? 'rotate(45deg)' : 'rotate(0)',
+                transition: 'transform 0.2s ease'
+              }}>
+                +
+              </span>
+            </div>
+            
+            {openItems.includes(index) && (
+              <div style={{ 
+                marginTop: '15px',
+                padding: '15px',
+                backgroundColor: '#f8f9fa',
+                borderRadius: '8px',
+                color: '#6c757d',
+                lineHeight: 1.6
+              }}>
+                {item.answer}
+              </div>
+            )}
+          </div>
+        ))}
+      </div>
+    </div>
+  );
+};
+
+export default FAQ;

frontend/src/components/Layout/FooterLinks/Features/Features.tsx

@@ -0,0 +1,111 @@
+// frontend/src/components/Layou/FooterLinks/Features/Features.tsx
+import React from 'react';
+
+const Features: React.FC = () => {
+  const features = [
+    {
+      icon: "🤖",
+      title: "Automatisches Scheduling",
+      description: "Intelligenter Algorithmus erstellt optimale Schichtpläne basierend auf Verfügbarkeiten und Regeln"
+    },
+    {
+      icon: "⚡",
+      title: "Schnelle Berechnung",
+      description: "Google OR-Tools CP-SAT Solver findet Lösungen in maximal 105 Sekunden"
+    },
+    {
+      icon: "👥",
+      title: "Flexible Regelkonfiguration",
+      description: "Anpassbare Geschäftsregeln für Trainee-Betreuung, Alleinarbeit, Vertragstypen"
+    },
+    {
+      icon: "📊",
+      title: "Echtzeit-Validierung",
+      description: "Automatische Erkennung von Regelverletzungen und Konflikten"
+    },
+    {
+      icon: "🔒",
+      title: "Lokale Datenspeicherung",
+      description: "Alle Daten bleiben in Ihrer Infrastruktur - volle Kontrolle und Datenschutz"
+    },
+    {
+      icon: "🎯",
+      title: "Präferenz-basiert",
+      description: "Berücksichtigt Mitarbeiterwünsche für höhere Zufriedenheit"
+    }
+  ];
+
+  return (
+    <div style={{ padding: '40px 20px', maxWidth: '1000px', margin: '0 auto' }}>
+      <h1>✨ Funktionen</h1>
+      
+      <div style={{ 
+        backgroundColor: 'white', 
+        borderRadius: '12px', 
+        padding: '30px', 
+        marginTop: '20px',
+        boxShadow: '0 4px 6px rgba(0,0,0,0.1)',
+        border: '1px solid #e0e0e0'
+      }}>
+        <h2 style={{ color: '#2c3e50', textAlign: 'center', marginBottom: '40px' }}>
+          Alles, was Sie für die perfekte Schichtplanung benötigen
+        </h2>
+        
+        <div style={{ 
+          display: 'grid', 
+          gridTemplateColumns: 'repeat(auto-fit, minmax(300px, 1fr))', 
+          gap: '30px' 
+        }}>
+          {features.map((feature, index) => (
+            <div key={index} style={{
+              padding: '25px',
+              backgroundColor: '#f8f9fa',
+              borderRadius: '12px',
+              border: '2px solid #e9ecef',
+              textAlign: 'center',
+              transition: 'transform 0.2s ease, box-shadow 0.2s ease'
+            }}>
+              <div style={{ 
+                fontSize: '3rem',
+                marginBottom: '15px'
+              }}>
+                {feature.icon}
+              </div>
+              <h3 style={{ 
+                color: '#2c3e50',
+                margin: '0 0 15px 0'
+              }}>
+                {feature.title}
+              </h3>
+              <p style={{ 
+                color: '#6c757d',
+                margin: 0,
+                lineHeight: 1.5
+              }}>
+                {feature.description}
+              </p>
+            </div>
+          ))}
+        </div>
+        
+        <div style={{ 
+          marginTop: '40px',
+          padding: '25px',
+          backgroundColor: '#e8f4fd',
+          borderRadius: '12px',
+          border: '2px solid #b8d4f0',
+          textAlign: 'center'
+        }}>
+          <h3 style={{ color: '#2980b9', margin: '0 0 15px 0' }}>
+            🚀 Starter Sie durch
+          </h3>
+          <p style={{ color: '#2c3e50', margin: 0 }}>
+            Erstellen Sie Ihren ersten optimierten Schichtplan in wenigen Minuten.
+          </p>
+        </div>
+      </div>
+    </div>
+  );
+};
+
+export default Features;

frontend/src/components/Layout/Layout.module.css

@@ -1,220 +0,0 @@
-/* Layout.css - Professionelles Design */
-.layout {
-  min-height: 100vh;
-  display: flex;
-  flex-direction: column;
-}
-
-/* Header */
-.header {
-  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
-  color: white;
-  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
-  position: sticky;
-  top: 0;
-  z-index: 1000;
-}
-
-.header-content {
-  max-width: 1200px;
-  margin: 0 auto;
-  padding: 0 20px;
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  height: 70px;
-}
-
-.logo h1 {
-  margin: 0;
-  font-size: 1.5rem;
-  font-weight: 700;
-}
-
-/* Desktop Navigation */
-.desktop-nav {
-  display: flex;
-  gap: 2rem;
-  align-items: center;
-}
-
-.nav-link {
-  color: white;
-  text-decoration: none;
-  padding: 0.5rem 1rem;
-  border-radius: 6px;
-  transition: all 0.3s ease;
-  font-weight: 500;
-}
-
-.nav-link:hover {
-  background: rgba(255, 255, 255, 0.1);
-  transform: translateY(-1px);
-}
-
-/* User Menu */
-.user-menu {
-  display: flex;
-  align-items: center;
-  gap: 1rem;
-}
-
-.user-info {
-  font-weight: 500;
-}
-
-.logout-btn {
-  background: rgba(255, 255, 255, 0.1);
-  color: white;
-  border: 1px solid rgba(255, 255, 255, 0.3);
-  padding: 0.5rem 1rem;
-  border-radius: 6px;
-  cursor: pointer;
-  transition: all 0.3s ease;
-}
-
-.logout-btn:hover {
-  background: rgba(255, 255, 255, 0.2);
-}
-
-/* Mobile Menu Button */
-.mobile-menu-btn {
-  display: none;
-  background: none;
-  border: none;
-  color: white;
-  font-size: 1.5rem;
-  cursor: pointer;
-  padding: 0.5rem;
-}
-
-/* Mobile Navigation */
-.mobile-nav {
-  display: none;
-  flex-direction: column;
-  background: white;
-  padding: 1rem;
-  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
-}
-
-.mobile-nav-link {
-  color: #333;
-  text-decoration: none;
-  padding: 1rem;
-  border-bottom: 1px solid #eee;
-  transition: background-color 0.3s ease;
-}
-
-.mobile-nav-link:hover {
-  background-color: #f5f5f5;
-}
-
-.mobile-user-info {
-  padding: 1rem;
-  border-top: 1px solid #eee;
-  margin-top: 1rem;
-}
-
-.mobile-logout-btn {
-  background: #667eea;
-  color: white;
-  border: none;
-  padding: 0.5rem 1rem;
-  border-radius: 6px;
-  cursor: pointer;
-  margin-top: 0.5rem;
-  width: 100%;
-}
-
-/* Main Content */
-.main-content {
-  flex: 1;
-  background-color: #f8f9fa;
-  min-height: calc(100vh - 140px);
-}
-
-.content-container {
-  max-width: 1200px;
-  margin: 0 auto;
-  padding: 2rem 20px;
-}
-
-/* Footer */
-.footer {
-  background: #2c3e50;
-  color: white;
-  margin-top: auto;
-}
-
-.footer-content {
-  max-width: 1200px;
-  margin: 0 auto;
-  padding: 2rem 20px;
-  display: grid;
-  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
-  gap: 2rem;
-}
-
-.footer-section h3,
-.footer-section h4 {
-  margin-bottom: 1rem;
-  color: #ecf0f1;
-}
-
-.footer-section a {
-  color: #bdc3c7;
-  text-decoration: none;
-  display: block;
-  margin-bottom: 0.5rem;
-  transition: color 0.3s ease;
-}
-
-.footer-section a:hover {
-  color: #3498db;
-}
-
-.footer-bottom {
-  border-top: 1px solid #34495e;
-  padding: 1rem 20px;
-  text-align: center;
-  color: #95a5a6;
-}
-
-/* Responsive Design */
-@media (max-width: 768px) {
-  .desktop-nav,
-  .user-menu {
-    display: none;
-  }
-  
-  .mobile-menu-btn {
-    display: block;
-  }
-  
-  .mobile-nav {
-    display: flex;
-  }
-  
-  .header-content {
-    padding: 0 15px;
-  }
-  
-  .content-container {
-    padding: 1rem 15px;
-  }
-  
-  .footer-content {
-    grid-template-columns: 1fr;
-    text-align: center;
-  }
-}
-
-@media (max-width: 480px) {
-  .logo h1 {
-    font-size: 1.2rem;
-  }
-  
-  .content-container {
-    padding: 1rem 10px;
-  }
-}

frontend/src/components/Layout/Layout.tsx

@@ -1,4 +1,4 @@
-// frontend/src/components/Layout/Layout.tsx - ELEGANT WHITE DESIGN
+// frontend/src/components/Layout/Layout.tsx
 import React from 'react';
 import Navigation from './Navigation';
 import Footer from './Footer';

frontend/src/components/Layout/Navigation.tsx

@@ -1,4 +1,4 @@
-// frontend/src/components/Layout/Navigation.tsx - ELEGANT WHITE DESIGN
+// frontend/src/components/Layout/Navigation.tsx
 import React, { useState, useEffect } from 'react';
 import { useAuth } from '../../contexts/AuthContext';
 import PillNav from '../PillNav/PillNav';

frontend/src/components/PillNav/PillNav.module.css

@@ -1,88 +0,0 @@
-/* frontend/src/components/PillNav/PillNav.module.css */
-.pillNavContainer {
-  display: flex;
-  gap: 8px;
-  overflow-x: auto;
-  padding: 4px;
-  scrollbar-width: none;
-  -ms-overflow-style: none;
-}
-
-.pillNavContainer::-webkit-scrollbar {
-  display: none;
-}
-
-.pill {
-  padding: 8px 16px;
-  border-radius: 9999px;
-  border: 1px solid;
-  font-size: 14px;
-  font-weight: 500;
-  cursor: pointer;
-  transition: all 0.2s ease-in-out;
-  white-space: nowrap;
-  outline: none;
-}
-
-.pill:focus-visible {
-  outline: 2px solid #3b82f6;
-  outline-offset: 2px;
-}
-
-/* Solid Variant */
-.pillSolid {
-  background-color: transparent;
-  color: #6b7280;
-  border-color: #d1d5db;
-}
-
-.pillSolidActive {
-  background-color: #2563eb;
-  color: white;
-  border-color: #2563eb;
-}
-
-.pillSolid:hover:not(.pillSolidActive) {
-  background-color: #f3f4f6;
-  color: #374151;
-  border-color: #9ca3af;
-  transform: translateY(-1px);
-}
-
-/* Outline Variant */
-.pillOutline {
-  background-color: transparent;
-  color: #6b7280;
-  border-color: #d1d5db;
-}
-
-.pillOutlineActive {
-  color: #2563eb;
-  border-color: #2563eb;
-  font-weight: 600;
-}
-
-.pillOutline:hover:not(.pillOutlineActive) {
-  background-color: #f3f4f6;
-  color: #374151;
-  border-color: #9ca3af;
-  transform: translateY(-1px);
-}
-
-/* Ghost Variant */
-.pillGhost {
-  background-color: transparent;
-  color: #6b7280;
-  border-color: transparent;
-}
-
-.pillGhostActive {
-  background-color: #f3f4f6;
-  color: #111827;
-}
-
-.pillGhost:hover:not(.pillGhostActive) {
-  background-color: #f9fafb;
-  color: #374151;
-  transform: translateY(-1px);
-}

frontend/src/components/PillNav/PillNav.tsx

@@ -1,4 +1,4 @@
-// frontend/src/components/PillNav/PillNav.tsx - ELEGANT WHITE DESIGN
+// frontend/src/components/PillNav/PillNav.tsx
 import React, { useEffect, useRef } from 'react';
 
 export interface PillNavItem {

frontend/src/components/PillNav/index.ts

@@ -1,3 +0,0 @@
-// frontend/src/components/PillNav/index.ts
-export { default } from './PillNav';
-export type { PillNavProps, PillNavItem } from './PillNav';

frontend/src/components/SecurityWarning/SecurityWarning.tsx

@@ -0,0 +1,59 @@
+// src/components/SecurityWarning/SecurityWarning.tsx
+import React, { useState, useEffect } from 'react';
+
+const SecurityWarning: React.FC = () => {
+  const [isHttp, setIsHttp] = useState(false);
+  const [isDismissed, setIsDismissed] = useState(false);
+
+  useEffect(() => {
+    // Check if current protocol is HTTP
+    const checkProtocol = () => {
+      setIsHttp(window.location.protocol === 'http:');
+    };
+
+    checkProtocol();
+    window.addEventListener('load', checkProtocol);
+    
+    return () => window.removeEventListener('load', checkProtocol);
+  }, []);
+
+  if (!isHttp || isDismissed) {
+    return null;
+  }
+
+  return (
+    <div style={{
+      position: 'fixed',
+      top: 0,
+      left: 0,
+      right: 0,
+      backgroundColor: '#ff6b35',
+      color: 'white',
+      padding: '10px 20px',
+      textAlign: 'center',
+      zIndex: 10000,
+      fontSize: '14px',
+      fontWeight: 'bold',
+      boxShadow: '0 2px 4px rgba(0,0,0,0.2)'
+    }}>
+      ⚠️ SECURITY WARNING: This site is being accessed over HTTP. 
+      For secure communication, please use HTTPS.
+      <button 
+        onClick={() => setIsDismissed(true)}
+        style={{
+          marginLeft: '15px',
+          background: 'rgba(255,255,255,0.2)',
+          border: '1px solid white',
+          color: 'white',
+          padding: '2px 8px',
+          borderRadius: '3px',
+          cursor: 'pointer'
+        }}
+      >
+        Dismiss
+      </button>
+    </div>
+  );
+};
+
+export default SecurityWarning;

frontend/src/components/StepSetup/StepSetup.stories.tsx

@@ -0,0 +1,79 @@
+import React from 'react';
+import type { Meta, StoryObj } from '@storybook/react';
+import StepSetup from './StepSetup';
+
+const meta: Meta<typeof StepSetup> = {
+  title: 'Components/StepSetup',
+  component: StepSetup,
+  parameters: {
+    layout: 'padded',
+  },
+  tags: ['autodocs'],
+};
+
+export default meta;
+type Story = StoryObj<typeof StepSetup>;
+
+const defaultSteps = [
+  { id: 'step-1', title: 'Account Setup', subtitle: 'Create your account' },
+  { id: 'step-2', title: 'Profile Information', subtitle: 'Add personal details' },
+  { id: 'step-3', title: 'Preferences', subtitle: 'Customize your experience', optional: true },
+  { id: 'step-4', title: 'Confirmation', subtitle: 'Review and confirm' },
+];
+
+export const Horizontal: Story = {
+  args: {
+    steps: defaultSteps,
+    defaultCurrent: 1,
+    orientation: 'horizontal',
+  },
+};
+
+export const Vertical: Story = {
+  args: {
+    steps: defaultSteps,
+    defaultCurrent: 1,
+    orientation: 'vertical',
+  },
+  parameters: {
+    layout: 'padded',
+  },
+};
+
+export const ClickableFalse: Story = {
+  args: {
+    steps: defaultSteps,
+    current: 2,
+    clickable: false,
+  },
+  name: 'Non-Clickable Steps',
+};
+
+export const AnimatedFalse: Story = {
+  args: {
+    steps: defaultSteps,
+    defaultCurrent: 1,
+    animated: false,
+  },
+  name: 'Without Animation',
+};
+
+export const DifferentSizes: Story = {
+  render: () => (
+    <div className="space-y-8">
+      <div>
+        <h3 className="text-sm font-medium mb-2">Small</h3>
+        <StepSetup steps={defaultSteps} size="sm" defaultCurrent={1} />
+      </div>
+      <div>
+        <h3 className="text-sm font-medium mb-2">Medium (default)</h3>
+        <StepSetup steps={defaultSteps} size="md" defaultCurrent={1} />
+      </div>
+      <div>
+        <h3 className="text-sm font-medium mb-2">Large</h3>
+        <StepSetup steps={defaultSteps} size="lg" defaultCurrent={1} />
+      </div>
+    </div>
+  ),
+  name: 'Different Sizes',
+};

frontend/src/components/StepSetup/StepSetup.test.tsx

@@ -0,0 +1,127 @@
+import React from 'react';
+import { render, screen, fireEvent } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import '@testing-library/jest-dom';
+import StepSetup from './StepSetup';
+
+const mockSteps = [
+  { id: 'step-1', title: 'First Step', subtitle: 'Description 1' },
+  { id: 'step-2', title: 'Second Step' },
+  { id: 'step-3', title: 'Third Step', subtitle: 'Description 3', optional: true },
+];
+
+describe('StepSetup', () => {
+  // a) Test verschiedener Step-Counts
+  test('renders correct number of steps', () => {
+    render(<StepSetup steps={mockSteps} />);
+    
+    expect(screen.getByText('First Step')).toBeInTheDocument();
+    expect(screen.getByText('Second Step')).toBeInTheDocument();
+    expect(screen.getByText('Third Step')).toBeInTheDocument();
+  });
+
+  test('renders empty state correctly', () => {
+    render(<StepSetup steps={[]} />);
+    
+    expect(screen.getByText('No steps available')).toBeInTheDocument();
+  });
+
+  // b) Keyboard-Navigation und Klicks
+  test('handles click navigation when clickable', async () => {
+    const user = userEvent.setup();
+    const onChange = jest.fn();
+    
+    render(<StepSetup steps={mockSteps} clickable={true} onChange={onChange} />);
+    
+    const secondStep = screen.getByRole('tab', { name: /second step/i });
+    await user.click(secondStep);
+    
+    expect(onChange).toHaveBeenCalledWith(1);
+  });
+
+  test('handles keyboard navigation', async () => {
+    const user = userEvent.setup();
+    const onChange = jest.fn();
+    
+    render(
+      <StepSetup 
+        steps={mockSteps} 
+        defaultCurrent={0} 
+        onChange={onChange} 
+      />
+    );
+
+    const firstStep = screen.getByRole('tab', { name: /first step/i });
+    firstStep.focus();
+    
+    // Right arrow to next step
+    await user.keyboard('{ArrowRight}');
+    expect(onChange).toHaveBeenCalledWith(1);
+    
+    // Home key to first step
+    await user.keyboard('{Home}');
+    expect(onChange).toHaveBeenCalledWith(0);
+    
+    // End key to last step  
+    await user.keyboard('{End}');
+    expect(onChange).toHaveBeenCalledWith(2);
+  });
+
+  // c) ARIA-Attribute Tests
+  test('has correct ARIA attributes', () => {
+    render(<StepSetup steps={mockSteps} current={1} />);
+    
+    const tablist = screen.getByRole('tablist');
+    expect(tablist).toBeInTheDocument();
+    
+    const tabs = screen.getAllByRole('tab');
+    expect(tabs).toHaveLength(3);
+    
+    // Second step should be selected
+    expect(tabs[1]).toHaveAttribute('aria-selected', 'true');
+    expect(tabs[1]).toHaveAttribute('aria-current', 'step');
+  });
+
+  // d) Controlled vs Uncontrolled Tests
+  test('works in controlled mode', () => {
+    const onChange = jest.fn();
+    
+    const { rerender } = render(
+      <StepSetup steps={mockSteps} current={0} onChange={onChange} />
+    );
+    
+    // Click should call onChange but not change internal state in controlled mode
+    const secondStep = screen.getByRole('tab', { name: /second step/i });
+    fireEvent.click(secondStep);
+    
+    expect(onChange).toHaveBeenCalledWith(1);
+    // Current step should still be first (controlled by prop)
+    expect(screen.getByRole('tab', { name: /first step/i }))
+      .toHaveAttribute('aria-selected', 'true');
+    
+    // Update prop should change current step
+    rerender(<StepSetup steps={mockSteps} current={1} onChange={onChange} />);
+    expect(screen.getByRole('tab', { name: /second step/i }))
+      .toHaveAttribute('aria-selected', 'true');
+  });
+
+  test('works in uncontrolled mode', () => {
+    const onChange = jest.fn();
+    
+    render(<StepSetup steps={mockSteps} defaultCurrent={0} onChange={onChange} />);
+    
+    const secondStep = screen.getByRole('tab', { name: /second step/i });
+    fireEvent.click(secondStep);
+    
+    expect(onChange).toHaveBeenCalledWith(1);
+    expect(secondStep).toHaveAttribute('aria-selected', 'true');
+  });
+
+  test('clamps out-of-range current values', () => {
+    render(<StepSetup steps={mockSteps} current={10} />);
+    
+    // Should clamp to last step
+    const lastStep = screen.getByRole('tab', { name: /third step/i });
+    expect(lastStep).toHaveAttribute('aria-selected', 'true');
+  });
+});

frontend/src/components/StepSetup/StepSetup.tsx

@@ -0,0 +1,516 @@
+import React, { 
+  useState, 
+  useEffect, 
+  useId, 
+  useCallback,
+  KeyboardEvent
+} from 'react';
+import { motion, MotionConfig, SpringOptions } from 'framer-motion';
+
+// ===== TYP-DEFINITIONEN =====
+export interface Step {
+  id: string;
+  title: string;
+  subtitle?: string;
+  optional?: boolean;
+}
+
+export interface StepSetupProps {
+  /** Array der Schritte mit ID, Titel und optionalen Eigenschaften */
+  steps: Step[];
+  /** Kontrollierter aktueller Schritt-Index */
+  current?: number;
+  /** Unkontrollierter Standard-Schritt-Index */
+  defaultCurrent?: number;
+  /** Callback bei Schrittänderung */
+  onChange?: (index: number) => void;
+  /** Ausrichtung des Steppers */
+  orientation?: 'horizontal' | 'vertical';
+  /** Ob Steps anklickbar sind */
+  clickable?: boolean;
+  /** Größe der Step-Komponente */
+  size?: 'sm' | 'md' | 'lg';
+  /** Animation aktivieren/deaktivieren */
+  animated?: boolean;
+  /** Zusätzliche CSS-Klassen */
+  className?: string;
+}
+
+export interface StepState {
+  currentStep: number;
+  isControlled: boolean;
+}
+
+// ===== HOOK FÜR ZUSTANDSVERWALTUNG =====
+export const useStepSetup = (props: StepSetupProps) => {
+  const {
+    steps,
+    current,
+    defaultCurrent = 0,
+    onChange,
+    clickable = true
+  } = props;
+
+  const [internalStep, setInternalStep] = useState(defaultCurrent);
+  const isControlled = current !== undefined;
+  
+  const currentStep = isControlled ? current : internalStep;
+
+  // Clamp den Schritt-Index auf gültigen Bereich
+  const clampedStep = Math.max(0, Math.min(currentStep, steps.length - 1));
+
+  const setStep = useCallback((newStep: number) => {
+    const clampedNewStep = Math.max(0, Math.min(newStep, steps.length - 1));
+    
+    if (!isControlled) {
+      setInternalStep(clampedNewStep);
+    }
+    
+    onChange?.(clampedNewStep);
+  }, [isControlled, onChange, steps.length]);
+
+  const goToNext = useCallback(() => {
+    if (clampedStep < steps.length - 1) {
+      setStep(clampedStep + 1);
+    }
+  }, [clampedStep, steps.length, setStep]);
+
+  const goToPrev = useCallback(() => {
+    if (clampedStep > 0) {
+      setStep(clampedStep - 1);
+    }
+  }, [clampedStep, setStep]);
+
+  const goToStep = useCallback((index: number) => {
+    if (clickable) {
+      setStep(index);
+    }
+  }, [clickable, setStep]);
+
+  // Warnung bei Duplicate IDs (nur in Development)
+  useEffect(() => {
+    if (process.env.NODE_ENV !== 'production') {
+      const stepIds = steps.map(step => step.id);
+      const duplicateIds = stepIds.filter((id, index) => stepIds.indexOf(id) !== index);
+      
+      if (duplicateIds.length > 0) {
+        console.warn(
+          `StepSetup: Duplicate step IDs found: ${duplicateIds.join(', ')}. ` +
+          `Step IDs should be unique.`
+        );
+      }
+    }
+  }, [steps]);
+
+  return {
+    currentStep: clampedStep,
+    setStep,
+    goToNext,
+    goToPrev,
+    goToStep,
+    isControlled
+  };
+};
+
+// ===== ANIMATIONS-KONFIGURATION =====
+const getAnimationConfig = (animated: boolean): { reduced: { duration: number }; normal: SpringOptions } => ({
+  reduced: { duration: 0 }, // Keine Animation
+  normal: {
+    stiffness: 500,
+    damping: 30,
+    mass: 0.5
+  }
+});
+
+// ===== HILFSFUNKTIONEN =====
+
+/**
+ * Berechnet die Step-Größenklassen basierend auf der size-Prop
+ */
+const getSizeClasses = (size: StepSetupProps['size'] = 'md') => {
+  const sizes = {
+    sm: {
+      step: 'w-8 h-8 text-sm',
+      icon: 'w-4 h-4',
+      title: 'text-sm',
+      subtitle: 'text-xs'
+    },
+    md: {
+      step: 'w-10 h-10 text-base',
+      icon: 'w-5 h-5',
+      title: 'text-base',
+      subtitle: 'text-sm'
+    },
+    lg: {
+      step: 'w-12 h-12 text-lg',
+      icon: 'w-6 h-6',
+      title: 'text-lg',
+      subtitle: 'text-base'
+    }
+  };
+  
+  return sizes[size];
+};
+
+/**
+ * Prüft ob prefers-reduced-motion aktiv ist
+ */
+const prefersReducedMotion = (): boolean => {
+  if (typeof window === 'undefined') return false;
+  return window.matchMedia('(prefers-reduced-motion: reduce)').matches;
+};
+
+// ===== STEP ICON KOMPONENTE =====
+interface StepIconProps {
+  stepIndex: number;
+  currentStep: number;
+  size: StepSetupProps['size'];
+  animated: boolean;
+}
+
+const StepNumber: React.FC<{ number: number; isCurrent?: boolean; isCompleted?: boolean }> = ({ 
+  number, 
+  isCurrent = false, 
+  isCompleted = false 
+}) => {
+  const baseClasses = `
+    w-6 h-6
+    flex items-center justify-center
+    rounded-full text-xs font-medium
+    transition-all duration-200
+  `;
+  
+  if (isCompleted) {
+    return (
+      <div className={`${baseClasses} bg-blue-500 text-white`}>
+        ✓
+      </div>
+    );
+  }
+  
+  if (isCurrent) {
+    return (
+      <div className={`${baseClasses} bg-blue-500 text-white ring-2 ring-blue-500 ring-opacity-20`}>
+        {number}
+      </div>
+    );
+  }
+  
+  return (
+    <div className={`${baseClasses} bg-gray-200 text-gray-600`}>
+      {number}
+    </div>
+  );
+};
+
+const StepIcon: React.FC<StepIconProps> = ({ 
+  stepIndex, 
+  currentStep, 
+  size,
+  animated 
+}) => {
+  const isCompleted = stepIndex < currentStep;
+  const isCurrent = stepIndex === currentStep;
+  
+  const sizeClasses = getSizeClasses(size);
+  const animationConfig = getAnimationConfig(animated);
+  const shouldAnimate = animated && !prefersReducedMotion();
+  
+  const baseClasses = `
+    ${sizeClasses.step}
+    flex items-center justify-center
+    rounded-full border-2 font-medium
+    transition-all duration-200
+  `;
+  
+  if (isCompleted) {
+    const completedClasses = `
+      ${baseClasses}
+      border-blue-500 bg-white
+    `;
+    
+    const iconContent = shouldAnimate ? (
+      <motion.div
+        initial={{ scale: 0, rotate: -180 }}
+        animate={{ scale: 1, rotate: 0 }}
+        transition={animationConfig.normal}
+      >
+        <StepNumber number={stepIndex + 1} isCompleted />
+      </motion.div>
+    ) : (
+      <StepNumber number={stepIndex + 1} isCompleted />
+    );
+    
+    return (
+      <div className={completedClasses}>
+        {iconContent}
+      </div>
+    );
+  }
+  
+  if (isCurrent) {
+    const currentClasses = `
+      ${baseClasses}
+      border-blue-500 bg-white
+    `;
+    
+    const stepNumber = shouldAnimate ? (
+      <motion.div
+        key={stepIndex}
+        initial={{ scale: 0 }}
+        animate={{ scale: 1 }}
+        transition={animationConfig.normal}
+      >
+        <StepNumber number={stepIndex + 1} isCurrent />
+      </motion.div>
+    ) : (
+      <StepNumber number={stepIndex + 1} isCurrent />
+    );
+    
+    return <div className={currentClasses}>{stepNumber}</div>;
+  }
+  
+  const upcomingClasses = `
+    ${baseClasses}
+    border-gray-300 bg-white
+  `;
+  
+  return (
+    <div className={upcomingClasses}>
+      <StepNumber number={stepIndex + 1} />
+    </div>
+  );
+};
+
+// ===== HAUPTKOMPONENTE =====
+
+/**
+ * Eine zugängliche, animierte Step/Progress-Komponente mit Unterstützung für 
+ * kontrollierte und unkontrollierte Verwendung.
+ * 
+ * @example
+ * ```tsx
+ * <StepSetup 
+ *   steps={[
+ *     { id: 's1', title: 'First Step', subtitle: 'Optional description' },
+ *     { id: 's2', title: 'Second Step' }
+ *   ]}
+ *   defaultCurrent={0}
+ *   onChange={(index) => console.log('Step changed:', index)}
+ * />
+ * ```
+ */
+const StepSetup: React.FC<StepSetupProps> = (props) => {
+  const {
+    steps,
+    orientation = 'horizontal',
+    clickable = true,
+    size = 'md',
+    animated = true,
+    className = ''
+  } = props;
+  
+  const {
+    currentStep,
+    goToStep
+  } = useStepSetup(props);
+  
+  const listId = useId();
+  const shouldAnimate = animated && !prefersReducedMotion();
+  const sizeClasses = getSizeClasses(size);
+  
+  // Fallback für leere Steps
+  if (!steps || steps.length === 0) {
+    return (
+      <div 
+        className={`flex items-center justify-center p-4 text-gray-500 ${className}`}
+        role="status"
+        aria-live="polite"
+      >
+        No steps available
+      </div>
+    );
+  }
+  
+  // Tastatur-Navigation Handler
+  const handleKeyDown = (
+    event: KeyboardEvent<HTMLButtonElement>, 
+    stepIndex: number
+  ) => {
+    if (!clickable) return;
+    
+    const isHorizontal = orientation === 'horizontal';
+    
+    switch (event.key) {
+      case 'Enter':
+      case ' ':
+        event.preventDefault();
+        goToStep(stepIndex);
+        break;
+        
+      case 'ArrowRight':
+      case 'ArrowDown':
+        if ((isHorizontal && event.key === 'ArrowRight') || 
+            (!isHorizontal && event.key === 'ArrowDown')) {
+          event.preventDefault();
+          const nextStep = Math.min(stepIndex + 1, steps.length - 1);
+          goToStep(nextStep);
+        }
+        break;
+        
+      case 'ArrowLeft':
+      case 'ArrowUp':
+        if ((isHorizontal && event.key === 'ArrowLeft') || 
+            (!isHorizontal && event.key === 'ArrowUp')) {
+          event.preventDefault();
+          const prevStep = Math.max(stepIndex - 1, 0);
+          goToStep(prevStep);
+        }
+        break;
+        
+      case 'Home':
+        event.preventDefault();
+        goToStep(0);
+        break;
+        
+      case 'End':
+        event.preventDefault();
+        goToStep(steps.length - 1);
+        break;
+    }
+  };
+  
+  // Container-Klassen basierend auf Ausrichtung
+  const containerClasses = `
+    flex ${orientation === 'vertical' ? 'flex-col' : 'flex-row'} 
+    ${orientation === 'horizontal' ? 'items-center justify-center gap-8' : 'gap-6'}
+    ${className}
+  `;
+  
+  const StepContent = shouldAnimate ? motion.div : 'div';
+  
+  return (
+    <MotionConfig reducedMotion={prefersReducedMotion() ? "always" : "user"}>
+      <nav 
+        className={containerClasses.trim()}
+        aria-label="Progress steps"
+        role="tablist"
+      >
+        {steps.map((step, index) => {
+          const isCompleted = index < currentStep;
+          const isCurrent = index === currentStep;
+          const isClickable = clickable && (isCompleted || isCurrent || step.optional);
+          
+          // Für horizontale Ausrichtung: flex-col mit zentrierten Items
+          const stepClasses = `
+            flex flex-col items-center
+            gap-3
+            ${isClickable ? 'cursor-pointer' : 'cursor-not-allowed'}
+            transition-colors duration-200
+            ${orientation === 'horizontal' ? 'flex-1' : ''}
+          `;
+          
+          const contentClasses = `
+            flex flex-col items-center text-center
+            ${orientation === 'vertical' ? 'flex-1' : ''}
+          `;
+          
+          // Verbindungslinie nur für horizontale Ausrichtung
+          const connectorClasses = `
+            flex-1 h-0.5 mt-5
+            ${isCompleted ? 'bg-blue-500' : 'bg-gray-200'}
+            transition-colors duration-200
+            ${orientation === 'horizontal' ? '' : 'hidden'}
+          `;
+          
+          return (
+            <React.Fragment key={step.id}>
+              <StepContent
+                className={stepClasses}
+                layout={shouldAnimate ? "position" : false}
+                transition={shouldAnimate ? getAnimationConfig(animated).normal : undefined}
+              >
+                <div className="flex items-center w-full">
+                  {/* Verbindungslinie vor dem Step (außer beim ersten) */}
+                  {index > 0 && orientation === 'horizontal' && (
+                    <div 
+                      className={connectorClasses}
+                      aria-hidden="true"
+                    />
+                  )}
+                  
+                  <button
+                    type="button"
+                    onClick={() => isClickable && goToStep(index)}
+                    onKeyDown={(e) => handleKeyDown(e, index)}
+                    disabled={!isClickable}
+                    className={`
+                      flex items-center justify-center
+                      focus:outline-none focus:ring-2 
+                      focus:ring-blue-500 focus:ring-offset-2 rounded-full
+                      ${!isClickable ? 'opacity-50' : ''}
+                      ${orientation === 'horizontal' ? 'mx-2' : ''}
+                    `}
+                    role="tab"
+                    aria-selected={isCurrent}
+                    aria-controls={`${listId}-${step.id}`}
+                    id={`${listId}-tab-${step.id}`}
+                    tabIndex={isCurrent ? 0 : -1}
+                    aria-current={isCurrent ? 'step' : undefined}
+                    aria-disabled={!isClickable}
+                  >
+                    <StepIcon 
+                      stepIndex={index}
+                      currentStep={currentStep}
+                      size={size}
+                      animated={animated}
+                    />
+                  </button>
+                  
+                  {/* Verbindungslinie nach dem Step (außer beim letzten) */}
+                  {index < steps.length - 1 && orientation === 'horizontal' && (
+                    <div 
+                      className={connectorClasses}
+                      aria-hidden="true"
+                    />
+                  )}
+                </div>
+                
+                {/* Step Titel und Untertitel */}
+                <div className={contentClasses}>
+                  <span 
+                    className={`
+                      font-medium
+                      ${isCurrent ? 'text-blue-600' : isCompleted ? 'text-gray-900' : 'text-gray-500'}
+                      ${sizeClasses.title}
+                    `}
+                    id={`${listId}-title-${step.id}`}
+                  >
+                    {step.title}
+                    {step.optional && (
+                      <span className="text-gray-400 text-sm ml-1">(Optional)</span>
+                    )}
+                  </span>
+                  
+                  {step.subtitle && (
+                    <span 
+                      className={`
+                        ${isCurrent ? 'text-gray-700' : 'text-gray-500'} 
+                        ${sizeClasses.subtitle}
+                      `}
+                      id={`${listId}-subtitle-${step.id}`}
+                    >
+                      {step.subtitle}
+                    </span>
+                  )}
+                </div>
+              </StepContent>
+            </React.Fragment>
+          );
+        })}
+      </nav>
+    </MotionConfig>
+  );
+};
+
+export default StepSetup;

frontend/src/contexts/AuthContext.tsx

@@ -20,7 +20,7 @@ interface AuthContextType {
 }
 
 const AuthContext = createContext<AuthContextType | undefined>(undefined);
-const API_BASE_URL = process.env.REACT_APP_API_BASE_URL || '/api';
+const API_BASE_URL = import.meta.env.VITE_API_URL || '/api';
 
 interface AuthProviderProps {
   children: ReactNode;
@@ -49,12 +49,21 @@ export const AuthProvider: React.FC<AuthProviderProps> = ({ children }) => {
   const checkSetupStatus = async (): Promise<void> => {
     try {
       console.log('🔍 Checking setup status...');
-      const response = await fetch(`${API_BASE_URL}/setup/status`);
+      const startTime = Date.now();
+      
+      const response = await fetch(`${API_BASE_URL}/setup/status`, {
+        signal: AbortSignal.timeout(5000)
+      });
+      
+      console.log(`✅ Setup status response received in ${Date.now() - startTime}ms`);
+      
       if (!response.ok) {
+        console.error('❌ Setup status response not OK:', response.status, response.statusText);
         throw new Error('Setup status check failed');
       }
+      
       const data = await response.json();
-      console.log('✅ Setup status response:', data);
+      console.log('✅ Setup status response data:', data);
       setNeedsSetup(data.needsSetup === true);
     } catch (error) {
       console.error('❌ Error checking setup status:', error);
@@ -95,7 +104,6 @@ export const AuthProvider: React.FC<AuthProviderProps> = ({ children }) => {
     }
   };
 
-  // Add the updateUser function
   const updateUser = (userData: Employee) => {
     console.log('🔄 Updating user in auth context:', userData);
     setUser(userData);
@@ -161,6 +169,8 @@ export const AuthProvider: React.FC<AuthProviderProps> = ({ children }) => {
     initializeAuth();
   }, []);
 
+  const calculatedNeedsSetup = needsSetup === null ? true : needsSetup;
+
   const value: AuthContextType = {
     user,
     login,
@@ -168,7 +178,7 @@ export const AuthProvider: React.FC<AuthProviderProps> = ({ children }) => {
     hasRole,
     loading,
     refreshUser,
-    needsSetup: needsSetup === null ? true : needsSetup,
+    needsSetup: calculatedNeedsSetup,
     checkSetupStatus,
     updateUser,
   };

frontend/src/design/DesignSystem.txt

@@ -1,4 +1,4 @@
-// frontend/src/design/DesignSystem.tsx
+// frontend/src/design/DesignSystem.txt
 export const designTokens = {
   colors: {
     // Primary Colors

frontend/src/hooks/useBackendValidation.ts

@@ -0,0 +1,73 @@
+// frontend/src/hooks/useBackendValidation.ts
+import { useState, useCallback } from 'react';
+import { ValidationError } from '../services/errorService';
+import { useNotification } from '../contexts/NotificationContext';
+
+export const useBackendValidation = () => {
+  const [validationErrors, setValidationErrors] = useState<ValidationError[]>([]);
+  const [isSubmitting, setIsSubmitting] = useState(false);
+  const { showNotification } = useNotification();
+
+  const clearErrors = useCallback(() => {
+    setValidationErrors([]);
+  }, []);
+
+  const getFieldError = useCallback((fieldName: string): string | null => {
+    const error = validationErrors.find(error => error.field === fieldName);
+    return error ? error.message : null;
+  }, [validationErrors]);
+
+  const hasErrors = useCallback((fieldName?: string): boolean => {
+    if (fieldName) {
+      return validationErrors.some(error => error.field === fieldName);
+    }
+    return validationErrors.length > 0;
+  }, [validationErrors]);
+
+  const executeWithValidation = useCallback(
+    async <T>(apiCall: () => Promise<T>): Promise<T> => {
+      setIsSubmitting(true);
+      clearErrors();
+
+      try {
+        const result = await apiCall();
+        return result;
+      } catch (error: any) {
+        if (error.validationErrors && Array.isArray(error.validationErrors)) {
+          setValidationErrors(error.validationErrors);
+
+          // Show specific validation error messages from backend
+          error.validationErrors.forEach((validationError: ValidationError, index: number) => {
+            setTimeout(() => {
+              showNotification({
+                type: 'error',
+                title: 'Validierungsfehler',
+                message: `${validationError.field ? `${validationError.field}: ` : ''}${validationError.message}`
+              });
+            }, index * 500); // Stagger the notifications
+          });
+        } else {
+          // Show notification for other errors
+          showNotification({
+            type: 'error',
+            title: 'Fehler',
+            message: error.message || 'Ein unerwarteter Fehler ist aufgetreten'
+          });
+        }
+        throw error;
+      } finally {
+        setIsSubmitting(false);
+      }
+    },
+    [clearErrors, showNotification]
+  );
+
+  return {
+    validationErrors,
+    isSubmitting,
+    clearErrors,
+    getFieldError,
+    hasErrors,
+    executeWithValidation,
+  };
+};

frontend/src/index.css

@@ -1,3 +1,14 @@
+/* Reset and base styles */
+* {
+  box-sizing: border-box;
+  margin: 0;
+  padding: 0;
+}
+
+#root {
+  min-height: 100vh;
+}
+
 body {
   margin: 0;
   font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',

frontend/src/index.tsx

@@ -1,19 +0,0 @@
-import React from 'react';
-import ReactDOM from 'react-dom/client';
-import './index.css';
-import App from './App';
-import reportWebVitals from './reportWebVitals';
-
-const root = ReactDOM.createRoot(
-  document.getElementById('root') as HTMLElement
-);
-root.render(
-  <React.StrictMode>
-    <App />
-  </React.StrictMode>
-);
-
-// If you want to start measuring performance in your app, pass a function
-// to log results (for example: reportWebVitals(console.log))
-// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
-reportWebVitals();

frontend/src/main.tsx

@@ -0,0 +1,10 @@
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import App from './App.tsx'
+import './index.css'
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>,
+)

frontend/src/models/defaults/employeeDefaults.ts

@@ -102,7 +102,7 @@ export const AVAILABILITY_PREFERENCES = {
 } as const;
 
 // Default availability for new employees (all shifts unavailable as level 3)
-// UPDATED: Now uses shiftId instead of timeSlotId + dayOfWeek
+// Now uses shiftId instead of timeSlotId + dayOfWeek
 export function createDefaultAvailabilities(employeeId: string, planId: string, shiftIds: string[]): Omit<EmployeeAvailability, 'id'>[] {
   const availabilities: Omit<EmployeeAvailability, 'id'>[] = [];
   

frontend/src/models/helpers/employeeHelpers.ts

@@ -18,12 +18,12 @@ function generateEmail(firstname: string, lastname: string): string {
   return `${cleanFirstname}.${cleanLastname}@sp.de`;
 }
 
-// UPDATED: Validation for new employee model with employee types
+// Validation for new employee model with employee types
 export function validateEmployeeData(employee: CreateEmployeeRequest): string[] {
   const errors: string[] = [];
 
-  if (employee.password?.length < 6) {
-    errors.push('Password must be at least 6 characters long');
+  if (employee.password?.length < 8) {
+    errors.push('Password must be at least 8 characters long');
   }
 
   if (!employee.firstname?.trim() || employee.firstname.trim().length < 2) {
@@ -71,7 +71,7 @@ export function generateEmployeeEmail(firstname: string, lastname: string): stri
   return generateEmail(firstname, lastname);
 }
 
-// UPDATED: Business logic helpers for new employee types
+// Business logic helpers for new employee types
 export const isManager = (employee: Employee): boolean =>
   employee.employeeType === 'manager';
 
@@ -90,7 +90,7 @@ export const isInternal = (employee: Employee): boolean =>
 export const isExternal = (employee: Employee): boolean =>
   employee.employeeType === 'guest';
 
-// UPDATED: Trainee logic - now based on isTrainee field for personell type
+// Trainee logic - now based on isTrainee field for personell type
 export const isTrainee = (employee: Employee): boolean =>
   employee.employeeType === 'personell' && employee.isTrainee;
 
@@ -107,7 +107,7 @@ export const isMaintenance = (employee: Employee): boolean =>
 export const isUser = (employee: Employee): boolean =>
   employee.roles?.includes('user') || false;
 
-// UPDATED: Work alone permission - managers and experienced personell can work alone
+// Work alone permission - managers and experienced personell can work alone
 export const canEmployeeWorkAlone = (employee: Employee): boolean =>
   employee.canWorkAlone && (isManager(employee) || isExperienced(employee));
 
@@ -134,7 +134,7 @@ export function validateAvailabilityData(availability: Omit<EmployeeAvailability
   return errors;
 }
 
-// UPDATED: Helper to get employee type category
+// Helper to get employee type category
 export const getEmployeeCategory = (employee: Employee): 'internal' | 'external' => {
   return isInternal(employee) ? 'internal' : 'external';
 };

frontend/src/models/helpers/shiftPlanHelpers.ts

@@ -78,7 +78,7 @@ export function calculateTotalRequiredEmployees(plan: ShiftPlan): number {
   return plan.shifts.reduce((total, shift) => total + shift.requiredEmployees, 0);
 }
 
-// UPDATED: Get scheduled shift by date and time slot
+// Get scheduled shift by date and time slot
 export function getScheduledShiftByDateAndTime(
   plan: ShiftPlan, 
   date: string, 

frontend/src/models/scheduling.ts

@@ -2,7 +2,7 @@
 import { Employee } from './Employee.js';
 import { ShiftPlan } from './ShiftPlan.js';
 
-// Updated Availability interface to match new schema
+// Availability interface to match
 export interface Availability {
   id: string;
   employeeId: string;

frontend/src/pages/Auth/Login.tsx

@@ -1,4 +1,4 @@
-// frontend/src/pages/Auth/Login.tsx - UPDATED PASSWORD SECTION
+// frontend/src/pages/Auth/Login.tsx
 import React, { useState, useEffect, useRef } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { useAuth } from '../../contexts/AuthContext';
@@ -129,7 +129,7 @@ const Login: React.FC = () => {
             onChange={(e) => setEmail(e.target.value)}
             required
             style={{
-              width: '94.5%',
+              width: '100%',
               padding: '10px',
               border: '1px solid #ddd',
               borderRadius: '4px',
@@ -151,7 +151,7 @@ const Login: React.FC = () => {
               onChange={(e) => setPassword(e.target.value)}
               required
               style={{
-                width: '94.5%',
+                width: '100%',
                 padding: '10px',
                 paddingRight: '10px',
                 border: '1px solid #ddd',

frontend/src/pages/Employees/components/AvailabilityManager.tsx

@@ -3,6 +3,8 @@ import { employeeService } from '../../../services/employeeService';
 import { shiftPlanService } from '../../../services/shiftPlanService';
 import { Employee, EmployeeAvailability } from '../../../models/Employee';
 import { ShiftPlan, TimeSlot, Shift } from '../../../models/ShiftPlan';
+import { useNotification } from '../../../contexts/NotificationContext';
+import { useBackendValidation } from '../../../hooks/useBackendValidation';
 
 interface AvailabilityManagerProps {
   employee: Employee;
@@ -36,7 +38,8 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
   const [selectedPlan, setSelectedPlan] = useState<ShiftPlan | null>(null);
   const [loading, setLoading] = useState(true);
   const [saving, setSaving] = useState(false);
-  const [error, setError] = useState('');
+  const { showNotification } = useNotification();
+  const { executeWithValidation, isSubmitting } = useBackendValidation();
 
   const daysOfWeek = [
     { id: 1, name: 'Montag' },
@@ -81,7 +84,11 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
 
       } catch (err: any) {
         console.error('❌ FEHLER BEIM LADEN DER INITIALDATEN:', err);
-        setError('Daten konnten nicht geladen werden: ' + (err.message || 'Unbekannter Fehler'));
+        showNotification({
+          type: 'error',
+          title: 'Fehler beim Laden',
+          message: 'Daten konnten nicht geladen werden: ' + (err.message || 'Unbekannter Fehler')
+        });
         setLoading(false);
       }
     };
@@ -134,9 +141,6 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
           );
           if (invalidAvailabilities.length > 0) {
             console.warn('⚠️ UNGÜLTIGE VERFÜGBARKEITEN (OHNE SHIFT-ID):', invalidAvailabilities.length);
-            invalidAvailabilities.forEach(invalid => {
-              console.warn('   - Ungültiger Eintrag:', invalid);
-            });
           }
           
           // Transformiere die Daten
@@ -149,11 +153,7 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
 
           // Debug: Zeige vorhandene Präferenzen
           if (planAvailabilities.length > 0) {
-            console.log('🎯 VORHANDENE PRÄFERENZEN:');
-            planAvailabilities.forEach(avail => {
-              const shift = plan.shifts?.find(s => s.id === avail.shiftId);
-              console.log(`   - Shift: ${avail.shiftId} (Day: ${shift?.dayOfWeek}), Level: ${avail.preferenceLevel}`);
-            });
+            console.log('🎯 VORHANDENE PRÄFERENZEN:', planAvailabilities.length);
           }
         } catch (availError) {
           console.error('❌ FEHLER BEIM LADEN DER VERFÜGBARKEITEN:', availError);
@@ -162,7 +162,11 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
 
       } catch (err: any) {
         console.error('❌ FEHLER BEIM LADEN DES SCHICHTPLANS:', err);
-        setError('Schichtplan konnte nicht geladen werden: ' + (err.message || 'Unbekannter Fehler'));
+        showNotification({
+          type: 'error',
+          title: 'Fehler beim Laden',
+          message: 'Schichtplan konnte nicht geladen werden: ' + (err.message || 'Unbekannter Fehler')
+        });
       } finally {
         setLoading(false);
       }
@@ -316,26 +320,6 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
       return (a.startTime || '').localeCompare(b.startTime || '');
     });
 
-    // Validation: Check if shifts are correctly placed
-    const validationErrors: string[] = [];
-    
-    // Check for missing time slots
-    const usedTimeSlotIds = new Set(selectedPlan?.shifts?.map(s => s.timeSlotId) || []);
-    const availableTimeSlotIds = new Set(selectedPlan?.timeSlots?.map(ts => ts.id) || []);
-
-    usedTimeSlotIds.forEach(timeSlotId => {
-      if (!availableTimeSlotIds.has(timeSlotId)) {
-        validationErrors.push(`Zeitslot ${timeSlotId} wird verwendet, existiert aber nicht in timeSlots`);
-      }
-    });
-
-    // Check for shifts with invalid day numbers
-    selectedPlan?.shifts?.forEach(shift => {
-      if (shift.dayOfWeek < 1 || shift.dayOfWeek > 7) {
-        validationErrors.push(`Shift ${shift.id} hat ungültigen Wochentag: ${shift.dayOfWeek}`);
-      }
-    });
-
     return (
       <div style={{
         marginBottom: '30px',
@@ -355,23 +339,6 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
           </div>
         </div>
 
-        {/* Validation Warnings */}
-        {validationErrors.length > 0 && (
-          <div style={{
-            backgroundColor: '#fff3cd',
-            border: '1px solid #ffeaa7',
-            padding: '15px',
-            margin: '10px'
-          }}>
-            <h4 style={{ margin: '0 0 10px 0', color: '#856404' }}>⚠️ Validierungswarnungen:</h4>
-            <ul style={{ margin: 0, paddingLeft: '20px', fontSize: '12px' }}>
-              {validationErrors.map((error, index) => (
-                <li key={index}>{error}</li>
-              ))}
-            </ul>
-          </div>
-        )}
-
         <div style={{ overflowX: 'auto' }}>
           <table style={{
             width: '100%',
@@ -421,9 +388,6 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                     <div style={{ fontSize: '14px', color: '#666' }}>
                       {formatTime(timeSlot.startTime)} - {formatTime(timeSlot.endTime)}
                     </div>
-                    <div style={{ fontSize: '11px', color: '#999', marginTop: '4px' }}>
-                      ID: {timeSlot.id.substring(0, 8)}...
-                    </div>
                   </td>
                   {days.map(weekday => {
                     const shift = timeSlot.shiftsByDay[weekday.id];
@@ -443,9 +407,6 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                       );
                     }
 
-                    // Validation: Check if shift has correct timeSlotId and dayOfWeek
-                    const isValidShift = shift.timeSlotId === timeSlot.id && shift.dayOfWeek === weekday.id;
-                    
                     const currentLevel = getAvailabilityForShift(shift.id);
                     const levelConfig = availabilityLevels.find(l => l.level === currentLevel);
                     
@@ -454,31 +415,8 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                         padding: '12px 16px',
                         border: '1px solid #dee2e6',
                         textAlign: 'center',
-                        backgroundColor: !isValidShift ? '#fff3cd' : (levelConfig?.bgColor || 'white'),
-                        position: 'relative'
+                        backgroundColor: levelConfig?.bgColor || 'white'
                       }}>
-                        {/* Validation indicator */}
-                        {!isValidShift && (
-                          <div style={{
-                            position: 'absolute',
-                            top: '2px',
-                            right: '2px',
-                            backgroundColor: '#f39c12',
-                            color: 'white',
-                            borderRadius: '50%',
-                            width: '16px',
-                            height: '16px',
-                            fontSize: '10px',
-                            display: 'flex',
-                            alignItems: 'center',
-                            justifyContent: 'center'
-                          }}
-                          title={`Shift Validierung: timeSlotId=${shift.timeSlotId}, dayOfWeek=${shift.dayOfWeek}`}
-                          >
-                            ⚠️
-                          </div>
-                        )}
-
                         <select
                           value={currentLevel}
                           onChange={(e) => {
@@ -487,10 +425,10 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                           }}
                           style={{
                             padding: '8px 12px',
-                            border: `2px solid ${!isValidShift ? '#f39c12' : (levelConfig?.color || '#ddd')}`,
+                            border: `2px solid ${levelConfig?.color || '#ddd'}`,
                             borderRadius: '6px',
-                            backgroundColor: !isValidShift ? '#fff3cd' : (levelConfig?.bgColor || 'white'),
-                            color: !isValidShift ? '#856404' : (levelConfig?.color || '#333'),
+                            backgroundColor: levelConfig?.bgColor || 'white',
+                            color: levelConfig?.color || '#333',
                             fontWeight: 'bold',
                             minWidth: '140px',
                             cursor: 'pointer',
@@ -511,23 +449,6 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                             </option>
                           ))}
                         </select>
-
-                        {/* Shift debug info */}
-                        <div style={{ 
-                          fontSize: '10px', 
-                          color: '#666', 
-                          marginTop: '4px',
-                          textAlign: 'left',
-                          fontFamily: 'monospace'
-                        }}>
-                          <div>Shift: {shift.id.substring(0, 6)}...</div>
-                          <div>Day: {shift.dayOfWeek}</div>
-                          {!isValidShift && (
-                            <div style={{ color: '#e74c3c', fontWeight: 'bold' }}>
-                              VALIDATION ERROR
-                            </div>
-                          )}
-                        </div>
                       </td>
                     );
                   })}
@@ -556,62 +477,34 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
   };
 
   const handleSave = async () => {
-    try {
-      setSaving(true);
-      setError('');
-      
     if (!selectedPlanId) {
-        setError('Bitte wählen Sie einen Schichtplan aus');
+      showNotification({
+        type: 'error',
+        title: 'Fehler',
+        message: 'Bitte wählen Sie einen Schichtplan aus'
+      });
       return;
     }
 
-      // Filter availabilities to only include those with actual shifts AND valid shiftIds
+    // Basic frontend validation: Check if we have any availabilities to save
     const validAvailabilities = availabilities.filter(avail => {
-        // Check if this shiftId exists and is valid
-        if (!avail.shiftId) {
-          console.warn('⚠️ Überspringe ungültige Verfügbarkeit ohne Shift-ID:', avail);
-          return false;
-        }
-        
-        // Check if this shiftId exists in the current plan
-        return selectedPlan?.shifts?.some(shift => shift.id === avail.shiftId);
-      });
-
-      console.log('💾 SPEICHERE VERFÜGBARKEITEN:', {
-        total: availabilities.length,
-        valid: validAvailabilities.length,
-        invalid: availabilities.length - validAvailabilities.length
+      return avail.shiftId && selectedPlan?.shifts?.some(shift => shift.id === avail.shiftId);
     });
 
     if (validAvailabilities.length === 0) {
-        setError('Keine gültigen Verfügbarkeiten zum Speichern gefunden');
+      showNotification({
+        type: 'error',
+        title: 'Fehler',
+        message: 'Keine gültigen Verfügbarkeiten zum Speichern gefunden'
+      });
       return;
     }
 
-      // Contract type validation
-      const availableShifts = validAvailabilities.filter(avail => 
-        avail.preferenceLevel === 1 || avail.preferenceLevel === 2
-      ).length;
+    // Complex validation (contract type rules) is now handled by backend
+    // We only do basic required field validation in frontend
 
-      let contractRequirement = 0;
-      let contractTypeName = '';
-
-      if (employee.contractType === 'small') {
-        contractRequirement = 2;
-        contractTypeName = 'Kleiner Vertrag';
-      } else if (employee.contractType === 'large') {
-        contractRequirement = 3;
-        contractTypeName = 'Großer Vertrag';
-      }
-
-      if (contractRequirement > 0 && availableShifts < contractRequirement) {
-        setError(
-          `${contractTypeName} erfordert mindestens ${contractRequirement} verfügbare Shifts. ` +
-          `Aktuell sind nur ${availableShifts} Shifts mit Verfügbarkeit "Bevorzugt" oder "Möglich" ausgewählt.`
-        );
-        setSaving(false);
-        return;
-      }
+    await executeWithValidation(async () => {
+      setSaving(true);
       
       // Convert to the format expected by the API - using shiftId directly
       const requestData = {
@@ -627,15 +520,16 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
       await employeeService.updateAvailabilities(employee.id, requestData);
       console.log('✅ VERFÜGBARKEITEN ERFOLGREICH GESPEICHERT');
 
+      showNotification({
+        type: 'success',
+        title: 'Erfolg',
+        message: 'Verfügbarkeiten wurden erfolgreich gespeichert'
+      });
+
       window.dispatchEvent(new CustomEvent('availabilitiesChanged'));
       
       onSave();
-    } catch (err: any) {
-      console.error('❌ FEHLER BEIM SPEICHERN:', err);
-      setError(err.message || 'Fehler beim Speichern der Verfügbarkeiten');
-    } finally {
-      setSaving(false);
-    }
+    });
   };
 
   if (loading) {
@@ -658,12 +552,11 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
   // Get full name for display
   const employeeFullName = `${employee.firstname} ${employee.lastname}`;
 
-  // Mininmum amount of shifts per contract type
+  // Available shifts count for display only (not for validation)
   const availableShiftsCount = availabilities.filter(avail => 
     avail.preferenceLevel === 1 || avail.preferenceLevel === 2
   ).length;
 
-
   return (
     <div style={{
       maxWidth: '1900px',
@@ -694,26 +587,14 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
         {employee.contractType && (
           <p style={{ margin: '5px 0 0 0', color: employee.contractType === 'small' ? '#f39c12' : '#27ae60' }}>
             <strong>Vertrag:</strong> 
-            {employee.contractType === 'small' ? ' Kleiner Vertrag (min. 2 verfügbare Shifts)' : 
-            employee.contractType === 'large' ? ' Großer Vertrag (min. 3 verfügbare Shifts)' : 
+            {employee.contractType === 'small' ? ' Kleiner Vertrag' : 
+            employee.contractType === 'large' ? ' Großer Vertrag' : 
             ' Flexibler Vertrag'}
+            {/* Note: Contract validation is now handled by backend */}
           </p>
         )}
       </div>
 
-      {error && (
-        <div style={{
-          backgroundColor: '#fee',
-          border: '1px solid #f5c6cb',
-          color: '#721c24',
-          padding: '12px',
-          borderRadius: '6px',
-          marginBottom: '20px'
-        }}>
-          <strong>Fehler:</strong> {error}
-        </div>
-      )}
-
       {/* Availability Legend */}
       <div style={{
         marginBottom: '30px',
@@ -774,7 +655,6 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
                 const newPlanId = e.target.value;
                 console.log('🔄 PLAN WECHSELN ZU:', newPlanId);
                 setSelectedPlanId(newPlanId);
-                // Der useEffect wird automatisch ausgelöst
               }}
               style={{
                 padding: '8px 12px',
@@ -828,15 +708,15 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
       }}>
         <button
           onClick={onCancel}
-          disabled={saving}
+          disabled={isSubmitting}
           style={{
             padding: '12px 24px',
             backgroundColor: '#95a5a6',
             color: 'white',
             border: 'none',
             borderRadius: '6px',
-            cursor: saving ? 'not-allowed' : 'pointer',
-            opacity: saving ? 0.6 : 1
+            cursor: isSubmitting ? 'not-allowed' : 'pointer',
+            opacity: isSubmitting ? 0.6 : 1
           }}
         >
           Abbrechen
@@ -844,18 +724,18 @@ const AvailabilityManager: React.FC<AvailabilityManagerProps> = ({
         
         <button
           onClick={handleSave}
-          disabled={saving || shiftsCount === 0 || !selectedPlanId}
+          disabled={isSubmitting || shiftsCount === 0 || !selectedPlanId}
           style={{
             padding: '12px 24px',
-            backgroundColor: saving ? '#bdc3c7' : (shiftsCount === 0 || !selectedPlanId ? '#95a5a6' : '#3498db'),
+            backgroundColor: isSubmitting ? '#bdc3c7' : (shiftsCount === 0 || !selectedPlanId ? '#95a5a6' : '#3498db'),
             color: 'white',
             border: 'none',
             borderRadius: '6px',
-            cursor: (saving || shiftsCount === 0 || !selectedPlanId) ? 'not-allowed' : 'pointer',
+            cursor: (isSubmitting || shiftsCount === 0 || !selectedPlanId) ? 'not-allowed' : 'pointer',
             fontWeight: 'bold'
           }}
         >
-          {saving ? '⏳ Wird gespeichert...' : `Verfügbarkeiten speichern (${availableShiftsCount})`}
+          {isSubmitting ? '⏳ Wird gespeichert...' : `Verfügbarkeiten speichern (${availableShiftsCount})`}
         </button>
       </div>
     </div>

frontend/src/pages/Employees/components/EmployeeList.tsx

@@ -3,6 +3,7 @@ import React, { useState } from 'react';
 import { ROLE_CONFIG, EMPLOYEE_TYPE_CONFIG } from '../../../models/defaults/employeeDefaults';
 import { Employee } from '../../../models/Employee';
 import { useAuth } from '../../../contexts/AuthContext';
+import { useNotification } from '../../../contexts/NotificationContext';
 
 interface EmployeeListProps {
   employees: Employee[];
@@ -14,7 +15,7 @@ interface EmployeeListProps {
 type SortField = 'name' | 'employeeType' | 'canWorkAlone' | 'role' | 'lastLogin';
 type SortDirection = 'asc' | 'desc';
 
-// FIXED: Use the actual employee types from the Employee interface
+// Use the actual employee types from the Employee interface
 type EmployeeType = 'manager' | 'personell' | 'apprentice' | 'guest';
 
 const EmployeeList: React.FC<EmployeeListProps> = ({
@@ -28,6 +29,7 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
   const [sortField, setSortField] = useState<SortField>('name');
   const [sortDirection, setSortDirection] = useState<SortDirection>('asc');
   const { user: currentUser, hasRole } = useAuth();
+  const { showNotification, confirmDialog } = useNotification();
 
   // Filter employees based on active/inactive and search term
   const filteredEmployees = employees.filter(employee => {
@@ -128,7 +130,7 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
   const getEmployeeTypeBadge = (type: EmployeeType, isTrainee: boolean = false) => {
     const config = EMPLOYEE_TYPE_CONFIG[type];
 
-    // FIXED: Updated color mapping for actual employee types
+    // Color mapping for actual employee types
     const bgColor =
       type === 'manager'
         ? '#fadbd8' // light red
@@ -176,6 +178,31 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
     return 'MITARBEITER';
   };
 
+  const handleDeleteClick = async (employee: Employee) => {
+    const confirmed = await confirmDialog({
+      title: 'Mitarbeiter löschen',
+      message: `Sind Sie sicher, dass Sie ${employee.firstname} ${employee.lastname} löschen möchten? Diese Aktion kann nicht rückgängig gemacht werden.`,
+      confirmText: 'Löschen',
+      cancelText: 'Abbrechen',
+      type: 'warning'
+    });
+
+    if (confirmed) {
+      try {
+        onDelete(employee);
+        showNotification({
+          type: 'success',
+          title: 'Erfolg',
+          message: `${employee.firstname} ${employee.lastname} wurde erfolgreich gelöscht.`
+        });
+      } catch (error: any) {
+        // Error will be handled by parent component through useBackendValidation
+        // We just need to re-throw it so the parent can catch it
+        throw error;
+      }
+    }
+  };
+
   if (employees.length === 0) {
     return (
       <div style={{
@@ -299,7 +326,7 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
         </div>
 
         {sortedEmployees.map(employee => {
-          // FIXED: Type assertion to ensure type safety
+          // Type assertion to ensure type safety
           const employeeType = getEmployeeTypeBadge(employee.employeeType as EmployeeType, employee.isTrainee);
           const independence = getIndependenceBadge(employee.canWorkAlone);
           const roleInfo = getRoleBadge(employee.roles);
@@ -468,7 +495,7 @@ const EmployeeList: React.FC<EmployeeListProps> = ({
                 {/* Löschen Button */}
                 {canDelete && (
                   <button
-                    onClick={() => onDelete(employee)}
+                    onClick={() => handleDeleteClick(employee)}
                     style={{
                       padding: '6px 8px',
                       backgroundColor: '#e74c3c',

frontend/src/pages/Settings/Settings.tsx

@@ -1,8 +1,9 @@
-// frontend/src/pages/Settings/Settings.tsx - UPDATED WITH NEW STYLES
+// frontend/src/pages/Settings/Settings.tsx - UPDATED WITH VALIDATION STRATEGY
 import React, { useState, useEffect, useRef } from 'react';
 import { useAuth } from '../../contexts/AuthContext';
 import { employeeService } from '../../services/employeeService';
 import { useNotification } from '../../contexts/NotificationContext';
+import { useBackendValidation } from '../../hooks/useBackendValidation';
 import AvailabilityManager from '../Employees/components/AvailabilityManager';
 import { Employee } from '../../models/Employee';
 import { styles } from './type/SettingsType';
@@ -10,11 +11,12 @@ import { styles } from './type/SettingsType';
 const Settings: React.FC = () => {
   const { user: currentUser, updateUser } = useAuth();
   const { showNotification } = useNotification();
+  const { executeWithValidation, clearErrors, isSubmitting } = useBackendValidation();
+
   const [activeTab, setActiveTab] = useState<'profile' | 'password' | 'availability'>('profile');
-  const [loading, setLoading] = useState(false);
   const [showAvailabilityManager, setShowAvailabilityManager] = useState(false);
 
-  // Profile form state - updated for firstname/lastname
+  // Profile form state
   const [profileForm, setProfileForm] = useState({
     firstname: currentUser?.firstname || '',
     lastname: currentUser?.lastname || ''
@@ -73,7 +75,7 @@ const Settings: React.FC = () => {
     }));
   };
 
-  // Password visibility handlers for current password
+  // Password visibility handlers
   const handleCurrentPasswordMouseDown = () => {
     currentPasswordTimeoutRef.current = setTimeout(() => {
       setShowCurrentPassword(true);
@@ -88,7 +90,6 @@ const Settings: React.FC = () => {
     setShowCurrentPassword(false);
   };
 
-  // Password visibility handlers for new password
   const handleNewPasswordMouseDown = () => {
     newPasswordTimeoutRef.current = setTimeout(() => {
       setShowNewPassword(true);
@@ -103,7 +104,6 @@ const Settings: React.FC = () => {
     setShowNewPassword(false);
   };
 
-  // Password visibility handlers for confirm password
   const handleConfirmPasswordMouseDown = () => {
     confirmPasswordTimeoutRef.current = setTimeout(() => {
       setShowConfirmPassword(true);
@@ -129,7 +129,6 @@ const Settings: React.FC = () => {
     cleanup();
   };
 
-  // Prevent context menu
   const handleContextMenu = (e: React.MouseEvent) => {
     e.preventDefault();
   };
@@ -138,40 +137,46 @@ const Settings: React.FC = () => {
     e.preventDefault();
     if (!currentUser) return;
 
-    // Validation
-    if (!profileForm.firstname.trim() || !profileForm.lastname.trim()) {
+    // BASIC FRONTEND VALIDATION: Only check required fields
+    if (!profileForm.firstname.trim()) {
       showNotification({
         type: 'error',
         title: 'Fehler',
-        message: 'Vorname und Nachname sind erforderlich'
+        message: 'Vorname ist erforderlich'
+      });
+      return;
+    }
+
+    if (!profileForm.lastname.trim()) {
+      showNotification({
+        type: 'error',
+        title: 'Fehler',
+        message: 'Nachname ist erforderlich'
       });
       return;
     }
 
     try {
-      setLoading(true);
-      await employeeService.updateEmployee(currentUser.id, {
+      // Use executeWithValidation to handle backend validation
+      await executeWithValidation(async () => {
+        const updatedEmployee = await employeeService.updateEmployee(currentUser.id, {
           firstname: profileForm.firstname.trim(),
           lastname: profileForm.lastname.trim()
         });
 
         // Update the auth context with new user data
-      const updatedUser = await employeeService.getEmployee(currentUser.id);
-      updateUser(updatedUser);
+        updateUser(updatedEmployee);
 
         showNotification({
           type: 'success',
           title: 'Erfolg',
           message: 'Profil erfolgreich aktualisiert'
         });
-    } catch (error: any) {
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: error.message || 'Profil konnte nicht aktualisiert werden'
       });
-    } finally {
-      setLoading(false);
+    } catch (error) {
+      // Backend validation errors are already handled by executeWithValidation
+      // We only need to handle unexpected errors here
+      console.error('Unexpected error:', error);
     }
   };
 
@@ -179,12 +184,30 @@ const Settings: React.FC = () => {
     e.preventDefault();
     if (!currentUser) return;
 
-    // Validation
-    if (passwordForm.newPassword.length < 6) {
+    // BASIC FRONTEND VALIDATION: Only check minimum requirements
+    if (!passwordForm.currentPassword) {
       showNotification({
         type: 'error',
         title: 'Fehler',
-        message: 'Das neue Passwort muss mindestens 6 Zeichen lang sein'
+        message: 'Aktuelles Passwort ist erforderlich'
+      });
+      return;
+    }
+
+    if (!passwordForm.newPassword) {
+      showNotification({
+        type: 'error',
+        title: 'Fehler',
+        message: 'Neues Passwort ist erforderlich'
+      });
+      return;
+    }
+
+    if (passwordForm.newPassword.length < 8) {
+      showNotification({
+        type: 'error',
+        title: 'Fehler',
+        message: 'Das neue Passwort muss mindestens 8 Zeichen lang sein'
       });
       return;
     }
@@ -199,12 +222,12 @@ const Settings: React.FC = () => {
     }
 
     try {
-      setLoading(true);
-      
-      // Use the actual password change endpoint
+      // Use executeWithValidation to handle backend validation
+      await executeWithValidation(async () => {
         await employeeService.changePassword(currentUser.id, {
           currentPassword: passwordForm.currentPassword,
-        newPassword: passwordForm.newPassword
+          newPassword: passwordForm.newPassword,
+          confirmPassword: passwordForm.confirmPassword
         });
 
         showNotification({
@@ -219,14 +242,10 @@ const Settings: React.FC = () => {
           newPassword: '',
           confirmPassword: ''
         });
-    } catch (error: any) {
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: error.message || 'Passwort konnte nicht geändert werden'
       });
-    } finally {
-      setLoading(false);
+    } catch (error) {
+      // Backend validation errors are already handled by executeWithValidation
+      console.error('Unexpected error:', error);
     }
   };
 
@@ -243,6 +262,12 @@ const Settings: React.FC = () => {
     setShowAvailabilityManager(false);
   };
 
+  // Clear validation errors when switching tabs
+  const handleTabChange = (tab: 'profile' | 'password' | 'availability') => {
+    clearErrors();
+    setActiveTab(tab);
+  };
+
   if (!currentUser) {
     return <div style={{
       textAlign: 'center',
@@ -273,7 +298,7 @@ const Settings: React.FC = () => {
 
         <div style={styles.tabs}>
           <button
-            onClick={() => setActiveTab('profile')}
+            onClick={() => handleTabChange('profile')}
             style={{
               ...styles.tab,
               ...(activeTab === 'profile' ? styles.tabActive : {})
@@ -301,7 +326,7 @@ const Settings: React.FC = () => {
           </button>
 
           <button
-            onClick={() => setActiveTab('password')}
+            onClick={() => handleTabChange('password')}
             style={{
               ...styles.tab,
               ...(activeTab === 'password' ? styles.tabActive : {})
@@ -329,7 +354,7 @@ const Settings: React.FC = () => {
           </button>
 
           <button
-            onClick={() => setActiveTab('availability')}
+            onClick={() => handleTabChange('availability')}
             style={{
               ...styles.tab,
               ...(activeTab === 'availability' ? styles.tabActive : {})
@@ -480,28 +505,28 @@ const Settings: React.FC = () => {
               <div style={styles.actions}>
                 <button
                   type="submit"
-                  disabled={loading || !profileForm.firstname.trim() || !profileForm.lastname.trim()}
+                  disabled={isSubmitting || !profileForm.firstname.trim() || !profileForm.lastname.trim()}
                   style={{
                     ...styles.button,
                     ...styles.buttonPrimary,
-                    ...((loading || !profileForm.firstname.trim() || !profileForm.lastname.trim()) ? styles.buttonDisabled : {})
+                    ...((isSubmitting || !profileForm.firstname.trim() || !profileForm.lastname.trim()) ? styles.buttonDisabled : {})
                   }}
                   onMouseEnter={(e) => {
-                    if (!loading && profileForm.firstname.trim() && profileForm.lastname.trim()) {
+                    if (!isSubmitting && profileForm.firstname.trim() && profileForm.lastname.trim()) {
                       e.currentTarget.style.background = styles.buttonPrimaryHover.background;
                       e.currentTarget.style.transform = styles.buttonPrimaryHover.transform;
                       e.currentTarget.style.boxShadow = styles.buttonPrimaryHover.boxShadow;
                     }
                   }}
                   onMouseLeave={(e) => {
-                    if (!loading && profileForm.firstname.trim() && profileForm.lastname.trim()) {
+                    if (!isSubmitting && profileForm.firstname.trim() && profileForm.lastname.trim()) {
                       e.currentTarget.style.background = styles.buttonPrimary.background;
                       e.currentTarget.style.transform = 'none';
                       e.currentTarget.style.boxShadow = styles.buttonPrimary.boxShadow;
                     }
                   }}
                 >
-                  {loading ? '⏳ Wird gespeichert...' : 'Profil aktualisieren'}
+                  {isSubmitting ? '⏳ Wird gespeichert...' : 'Profil aktualisieren'}
                 </button>
               </div>
             </form>
@@ -575,9 +600,9 @@ const Settings: React.FC = () => {
                       value={passwordForm.newPassword}
                       onChange={handlePasswordChange}
                       required
-                      minLength={6}
+                      minLength={8}
                       style={styles.fieldInputWithIcon}
-                      placeholder="Mindestens 6 Zeichen"
+                      placeholder="Mindestens 8 Zeichen"
                       onFocus={(e) => {
                         e.target.style.borderColor = '#1a1325';
                         e.target.style.boxShadow = '0 0 0 3px rgba(26, 19, 37, 0.1)';
@@ -606,7 +631,7 @@ const Settings: React.FC = () => {
                     </button>
                   </div>
                   <div style={styles.fieldHint}>
-                    Das Passwort muss mindestens 6 Zeichen lang sein.
+                    Das Passwort muss mindestens 8 Zeichen lang sein.
                   </div>
                 </div>
 
@@ -657,28 +682,28 @@ const Settings: React.FC = () => {
               <div style={styles.actions}>
                 <button
                   type="submit"
-                  disabled={loading || !passwordForm.currentPassword || !passwordForm.newPassword || !passwordForm.confirmPassword}
+                  disabled={isSubmitting || !passwordForm.currentPassword || !passwordForm.newPassword || !passwordForm.confirmPassword}
                   style={{
                     ...styles.button,
                     ...styles.buttonPrimary,
-                    ...((loading || !passwordForm.currentPassword || !passwordForm.newPassword || !passwordForm.confirmPassword) ? styles.buttonDisabled : {})
+                    ...((isSubmitting || !passwordForm.currentPassword || !passwordForm.newPassword || !passwordForm.confirmPassword) ? styles.buttonDisabled : {})
                   }}
                   onMouseEnter={(e) => {
-                    if (!loading && passwordForm.currentPassword && passwordForm.newPassword && passwordForm.confirmPassword) {
+                    if (!isSubmitting && passwordForm.currentPassword && passwordForm.newPassword && passwordForm.confirmPassword) {
                       e.currentTarget.style.background = styles.buttonPrimaryHover.background;
                       e.currentTarget.style.transform = styles.buttonPrimaryHover.transform;
                       e.currentTarget.style.boxShadow = styles.buttonPrimaryHover.boxShadow;
                     }
                   }}
                   onMouseLeave={(e) => {
-                    if (!loading && passwordForm.currentPassword && passwordForm.newPassword && passwordForm.confirmPassword) {
+                    if (!isSubmitting && passwordForm.currentPassword && passwordForm.newPassword && passwordForm.confirmPassword) {
                       e.currentTarget.style.background = styles.buttonPrimary.background;
                       e.currentTarget.style.transform = 'none';
                       e.currentTarget.style.boxShadow = styles.buttonPrimary.boxShadow;
                     }
                   }}
                 >
-                  {loading ? '⏳ Wird geändert...' : 'Passwort ändern'}
+                  {isSubmitting ? '⏳ Wird geändert...' : 'Passwort ändern'}
                 </button>
               </div>
             </form>

frontend/src/pages/Settings/type/SettingsType.tsx

@@ -1,4 +1,4 @@
-// frontend/src/pages/Settings/type/SettingsType.tsx - CORRECTED
+// frontend/src/pages/Settings/type/SettingsType.tsx
 export const styles = {
   container: {
     display: 'flex',

frontend/src/pages/Setup/Setup.tsx

@@ -1,12 +1,26 @@
-// frontend/src/pages/Setup/Setup.tsx - UPDATED
 import React, { useState } from 'react';
 import { useAuth } from '../../contexts/AuthContext';
 
 const API_BASE_URL = '/api';
 
-const Setup: React.FC = () => {
-  const [step, setStep] = useState(1);
-  const [formData, setFormData] = useState({
+// ===== TYP-DEFINITIONEN =====
+interface SetupFormData {
+  password: string;
+  confirmPassword: string;
+  firstname: string;
+  lastname: string;
+}
+
+interface SetupStep {
+  id: string;
+  title: string;
+  subtitle?: string;
+}
+
+// ===== HOOK FÜR SETUP-LOGIK =====
+const useSetup = () => {
+  const [currentStep, setCurrentStep] = useState(0);
+  const [formData, setFormData] = useState<SetupFormData>({
     password: '',
     confirmPassword: '',
     firstname: '',
@@ -16,27 +30,26 @@ const Setup: React.FC = () => {
   const [error, setError] = useState('');
   const { checkSetupStatus } = useAuth();
 
-  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
-    const { name, value } = e.target;
-    setFormData(prev => ({
-      ...prev,
-      [name]: value
-    }));
-  };
-
-  const validateStep1 = () => {
-    if (formData.password.length < 6) {
-      setError('Das Passwort muss mindestens 6 Zeichen lang sein.');
-      return false;
+  const steps: SetupStep[] = [
+    {
+      id: 'profile-setup',
+      title: 'Profilinformationen',
+      subtitle: 'Geben Sie Ihre persönlichen Daten ein'
+    },
+    {
+      id: 'password-setup',
+      title: 'Passwort erstellen',
+      subtitle: 'Legen Sie ein sicheres Passwort fest'
+    },
+    {
+      id: 'confirmation',
+      title: 'Bestätigung',
+      subtitle: 'Setup abschließen'
     }
-    if (formData.password !== formData.confirmPassword) {
-      setError('Die Passwörter stimmen nicht überein.');
-      return false;
-    }
-    return true;
-  };
+  ];
 
-  const validateStep2 = () => {
+  // ===== VALIDIERUNGS-FUNKTIONEN =====
+  const validateStep1 = (): boolean => {
     if (!formData.firstname.trim()) {
       setError('Bitte geben Sie einen Vornamen ein.');
       return false;
@@ -48,21 +61,78 @@ const Setup: React.FC = () => {
     return true;
   };
 
-  const handleNext = () => {
-    setError('');
-    if (step === 1 && validateStep1()) {
-      setStep(2);
-    } else if (step === 2 && validateStep2()) {
-      handleSubmit();
+  const validateStep2 = (): boolean => {
+    if (formData.password.length < 8) {
+      setError('Das Passwort muss mindestens 8 Zeichen lang sein.');
+      return false;
+    }
+    if (formData.password !== formData.confirmPassword) {
+      setError('Die Passwörter stimmen nicht überein.');
+      return false;
+    }
+    return true;
+  };
+
+  const validateCurrentStep = (stepIndex: number): boolean => {
+    switch (stepIndex) {
+      case 0:
+        return validateStep1();
+      case 1:
+        return validateStep2();
+      default:
+        return true;
     }
   };
 
-  const handleBack = () => {
+  // ===== NAVIGATIONS-FUNKTIONEN =====
+  const goToNextStep = async (): Promise<void> => {
     setError('');
-    setStep(1);
+
+    if (!validateCurrentStep(currentStep)) {
+      return;
+    }
+
+    // Wenn wir beim letzten Schritt sind, Submit ausführen
+    if (currentStep === steps.length - 1) {
+      await handleSubmit();
+      return;
+    }
+
+    // Ansonsten zum nächsten Schritt gehen
+    setCurrentStep(prev => prev + 1);
   };
 
-  const handleSubmit = async () => {
+  const goToPrevStep = (): void => {
+    setError('');
+    if (currentStep > 0) {
+      setCurrentStep(prev => prev - 1);
+    }
+  };
+
+  const handleStepChange = (stepIndex: number): void => {
+    setError('');
+
+    // Nur erlauben, zu bereits validierten Schritten zu springen
+    // oder zum nächsten Schritt nach dem aktuellen
+    if (stepIndex <= currentStep + 1) {
+      // Vor dem Wechsel validieren
+      if (stepIndex > currentStep && !validateCurrentStep(currentStep)) {
+        return;
+      }
+      setCurrentStep(stepIndex);
+    }
+  };
+
+  // ===== FORM HANDLER =====
+  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>): void => {
+    const { name, value } = e.target;
+    setFormData(prev => ({
+      ...prev,
+      [name]: value
+    }));
+  };
+
+  const handleSubmit = async (): Promise<void> => {
     try {
       setLoading(true);
       setError('');
@@ -102,8 +172,8 @@ const Setup: React.FC = () => {
     }
   };
 
-  // Helper to display generated email preview
-  const getEmailPreview = () => {
+  // ===== HELPER FUNCTIONS =====
+  const getEmailPreview = (): string => {
     if (!formData.firstname.trim() || !formData.lastname.trim()) {
       return 'vorname.nachname@sp.de';
     }
@@ -113,113 +183,51 @@ const Setup: React.FC = () => {
     return `${cleanFirstname}.${cleanLastname}@sp.de`;
   };
 
-  return (
-    <div style={{ 
-      minHeight: '100vh', 
-      backgroundColor: '#f8f9fa',
-      display: 'flex',
-      alignItems: 'center',
-      justifyContent: 'center',
-      padding: '2rem'
-    }}>
-      <div style={{
-        backgroundColor: 'white',
-        padding: '3rem',
-        borderRadius: '12px',
-        boxShadow: '0 10px 30px rgba(0,0,0,0.1)',
-        width: '100%',
-        maxWidth: '500px',
-        border: '1px solid #e9ecef'
-      }}>
-        <div style={{ textAlign: 'center', marginBottom: '2rem' }}>
-          <h1 style={{ 
-            fontSize: '2rem', 
-            fontWeight: 'bold', 
-            marginBottom: '0.5rem',
-            color: '#2c3e50'
-          }}>
-            🚀 Erstkonfiguration
-          </h1>
-          <p style={{ 
-            color: '#6c757d',
-            fontSize: '1.1rem'
-          }}>
-            Richten Sie Ihren Administrator-Account ein
-          </p>
-        </div>
+  const isStepCompleted = (stepIndex: number): boolean => {
+    switch (stepIndex) {
+      case 0:
+        return formData.password.length >= 8 &&
+          formData.password === formData.confirmPassword;
+      case 1:
+        return !!formData.firstname.trim() && !!formData.lastname.trim();
+      default:
+        return false;
+    }
+  };
 
-        {error && (
-          <div style={{
-            backgroundColor: '#f8d7da',
-            border: '1px solid #f5c6cb',
-            color: '#721c24',
-            padding: '1rem',
-            borderRadius: '6px',
-            marginBottom: '1.5rem'
-          }}>
-            {error}
-          </div>
-        )}
+  return {
+    // State
+    currentStep,
+    formData,
+    loading,
+    error,
+    steps,
 
-        {step === 1 && (
-          <div style={{ display: 'flex', flexDirection: 'column', gap: '1.5rem' }}>
-            <div>
-              <label style={{ 
-                display: 'block', 
-                marginBottom: '0.5rem', 
-                fontWeight: '600',
-                color: '#495057'
-              }}>
-                Passwort
-              </label>
-              <input
-                type="password"
-                name="password"
-                value={formData.password}
-                onChange={handleInputChange}
-                style={{
-                  width: '100%',
-                  padding: '0.75rem',
-                  border: '1px solid #ced4da',
-                  borderRadius: '6px',
-                  fontSize: '1rem',
-                  transition: 'border-color 0.3s ease'
-                }}
-                placeholder="Mindestens 6 Zeichen"
-                required
-              />
-            </div>
+    // Actions
+    goToNextStep,
+    goToPrevStep,
+    handleStepChange,
+    handleInputChange,
 
-            <div>
-              <label style={{ 
-                display: 'block', 
-                marginBottom: '0.5rem', 
-                fontWeight: '600',
-                color: '#495057'
-              }}>
-                Passwort bestätigen
-              </label>
-              <input
-                type="password"
-                name="confirmPassword"
-                value={formData.confirmPassword}
-                onChange={handleInputChange}
-                style={{
-                  width: '100%',
-                  padding: '0.75rem',
-                  border: '1px solid #ced4da',
-                  borderRadius: '6px',
-                  fontSize: '1rem',
-                  transition: 'border-color 0.3s ease'
-                }}
-                placeholder="Passwort wiederholen"
-                required
-              />
-            </div>
-          </div>
-        )}
+    // Helpers
+    getEmailPreview,
+    isStepCompleted
+  };
+};
 
-        {step === 2 && (
+// ===== STEP-INHALTS-KOMPONENTEN =====
+interface StepContentProps {
+  formData: SetupFormData;
+  onInputChange: (e: React.ChangeEvent<HTMLInputElement>) => void;
+  getEmailPreview: () => string;
+  currentStep: number;
+}
+
+const Step1Content: React.FC<StepContentProps> = ({
+  formData,
+  onInputChange,
+  getEmailPreview
+}) => (
   <div style={{ display: 'flex', flexDirection: 'column', gap: '1.5rem' }}>
     <div>
       <label style={{
@@ -234,7 +242,7 @@ const Setup: React.FC = () => {
         type="text"
         name="firstname"
         value={formData.firstname}
-                onChange={handleInputChange}
+        onChange={onInputChange}
         style={{
           width: '100%',
           padding: '0.75rem',
@@ -244,6 +252,7 @@ const Setup: React.FC = () => {
         }}
         placeholder="Max"
         required
+        autoComplete="given-name"
       />
     </div>
 
@@ -260,7 +269,7 @@ const Setup: React.FC = () => {
         type="text"
         name="lastname"
         value={formData.lastname}
-                onChange={handleInputChange}
+        onChange={onInputChange}
         style={{
           width: '100%',
           padding: '0.75rem',
@@ -270,6 +279,7 @@ const Setup: React.FC = () => {
         }}
         placeholder="Mustermann"
         required
+        autoComplete="family-name"
       />
     </div>
 
@@ -302,66 +312,381 @@ const Setup: React.FC = () => {
       </div>
     </div>
   </div>
+);
+
+
+const Step2Content: React.FC<StepContentProps> = ({
+  formData,
+  onInputChange
+}) => (
+  <div style={{ display: 'flex', flexDirection: 'column', gap: '1.5rem' }}>
+    <div>
+      <label style={{
+        display: 'block',
+        marginBottom: '0.5rem',
+        fontWeight: '600',
+        color: '#495057'
+      }}>
+        Passwort
+      </label>
+      <input
+        type="password"
+        name="password"
+        value={formData.password}
+        onChange={onInputChange}
+        style={{
+          width: '100%',
+          padding: '0.75rem',
+          border: '1px solid #ced4da',
+          borderRadius: '6px',
+          fontSize: '1rem',
+          transition: 'border-color 0.3s ease'
+        }}
+        placeholder="Mindestens 8 Zeichen"
+        required
+        autoComplete="new-password"
+      />
+    </div>
+
+    <div>
+      <label style={{
+        display: 'block',
+        marginBottom: '0.5rem',
+        fontWeight: '600',
+        color: '#495057'
+      }}>
+        Passwort bestätigen
+      </label>
+      <input
+        type="password"
+        name="confirmPassword"
+        value={formData.confirmPassword}
+        onChange={onInputChange}
+        style={{
+          width: '100%',
+          padding: '0.75rem',
+          border: '1px solid #ced4da',
+          borderRadius: '6px',
+          fontSize: '1rem',
+          transition: 'border-color 0.3s ease'
+        }}
+        placeholder="Passwort wiederholen"
+        required
+        autoComplete="new-password"
+      />
+    </div>
+  </div>
+);
+
+const Step3Content: React.FC<StepContentProps> = ({
+  formData,
+  getEmailPreview
+}) => (
+  <div style={{ display: 'flex', flexDirection: 'column', gap: '1.5rem' }}>
+    <div style={{
+      backgroundColor: '#f8f9fa',
+      padding: '1.5rem',
+      borderRadius: '8px',
+      border: '1px solid #e9ecef'
+    }}>
+      <h3 style={{
+        marginBottom: '1rem',
+        color: '#2c3e50',
+        fontSize: '1.1rem',
+        fontWeight: '600'
+      }}>
+        Zusammenfassung
+      </h3>
+
+      <div style={{ display: 'flex', flexDirection: 'column', gap: '0.75rem' }}>
+        <div style={{ display: 'flex', justifyContent: 'space-between' }}>
+          <span style={{ color: '#6c757d' }}>E-Mail:</span>
+          <span style={{ fontWeight: '500' }}>{getEmailPreview()}</span>
+        </div>
+        <div style={{ display: 'flex', justifyContent: 'space-between' }}>
+          <span style={{ color: '#6c757d' }}>Vorname:</span>
+          <span style={{ fontWeight: '500' }}>{formData.firstname || '-'}</span>
+        </div>
+        <div style={{ display: 'flex', justifyContent: 'space-between' }}>
+          <span style={{ color: '#6c757d' }}>Nachname:</span>
+          <span style={{ fontWeight: '500' }}>{formData.lastname || '-'}</span>
+        </div>
+      </div>
+    </div>
+
+    <div style={{
+      padding: '1rem',
+      backgroundColor: '#e7f3ff',
+      borderRadius: '6px',
+      border: '1px solid #b6d7e8',
+      color: '#2c3e50'
+    }}>
+      <strong>💡 Wichtig:</strong> Nach dem Setup können Sie sich mit Ihrer
+      automatisch generierten E-Mail anmelden.
+    </div>
+  </div>
+);
+
+// ===== HAUPTKOMPONENTE =====
+const Setup: React.FC = () => {
+  const {
+    currentStep,
+    formData,
+    loading,
+    error,
+    steps,
+    goToNextStep,
+    goToPrevStep,
+    handleStepChange,
+    handleInputChange,
+    getEmailPreview
+  } = useSetup();
+
+  const renderStepContent = (): React.ReactNode => {
+    const stepProps = {
+      formData,
+      onInputChange: handleInputChange,
+      getEmailPreview,
+      currentStep
+    };
+
+    switch (currentStep) {
+      case 0:
+        return <Step1Content {...stepProps} />;
+      case 1:
+        return <Step2Content {...stepProps} />;
+      case 2:
+        return <Step3Content {...stepProps} />;
+      default:
+        return null;
+    }
+  };
+
+  const getNextButtonText = (): string => {
+    if (loading) return '⏳ Wird verarbeitet...';
+
+    switch (currentStep) {
+      case 0:
+        return 'Weiter →';
+      case 1:
+        return 'Weiter →';
+      case 2:
+        return 'Setup abschließen';
+      default:
+        return 'Weiter →';
+    }
+  };
+
+  // Inline Step Indicator Komponente
+  const StepIndicator: React.FC = () => (
+    <div style={{
+      display: 'flex',
+      justifyContent: 'space-between',
+      alignItems: 'center',
+      marginBottom: '2.5rem',
+      position: 'relative',
+      width: '100%'
+    }}>
+      {/* Verbindungslinien */}
+      <div style={{
+        position: 'absolute',
+        top: '12px',
+        left: '0',
+        right: '0',
+        height: '2px',
+        backgroundColor: '#e9ecef',
+        zIndex: 1
+      }} />
+
+      {steps.map((step, index) => {
+        const isCompleted = index < currentStep;
+        const isCurrent = index === currentStep;
+        const isClickable = index <= currentStep + 1;
+
+        return (
+          <div
+            key={step.id}
+            style={{
+              display: 'flex',
+              flexDirection: 'column',
+              alignItems: 'center',
+              zIndex: 2,
+              position: 'relative',
+              flex: 1
+            }}
+          >
+            <button
+              onClick={() => isClickable && handleStepChange(index)}
+              disabled={!isClickable}
+              style={{
+                width: '28px',
+                height: '28px',
+                borderRadius: '50%',
+                border: '2px solid',
+                borderColor: isCompleted || isCurrent ? '#51258f' : '#e9ecef',
+                backgroundColor: isCompleted ? '#51258f' : 'white',
+                color: isCompleted ? 'white' : (isCurrent ? '#51258f' : '#6c757d'),
+                display: 'flex',
+                alignItems: 'center',
+                justifyContent: 'center',
+                fontSize: '14px',
+                fontWeight: 'bold',
+                cursor: isClickable ? 'pointer' : 'not-allowed',
+                transition: 'all 0.3s ease',
+                marginBottom: '8px'
+              }}
+            >
+              {index + 1}
+            </button>
+
+            <div style={{ textAlign: 'center' }}>
+              <div style={{
+                fontSize: '14px',
+                fontWeight: isCurrent ? '600' : '400',
+                color: isCurrent ? '#51258f' : '#6c757d'
+              }}>
+                {step.title}
+              </div>
+            </div>
+          </div>
+        );
+      })}
+    </div>
+  );
+
+  return (
+    <div style={{
+      minHeight: '100vh',
+      backgroundColor: '#f8f9fa',
+      display: 'flex',
+      alignItems: 'center',
+      justifyContent: 'center',
+      padding: '2rem'
+    }}>
+      <div style={{
+        backgroundColor: 'white',
+        padding: '3rem',
+        borderRadius: '12px',
+        boxShadow: '0 10px 30px rgba(0,0,0,0.1)',
+        width: '100%',
+        maxWidth: '600px',
+        border: '1px solid #e9ecef'
+      }}>
+        <div style={{ textAlign: 'center', marginBottom: '1rem' }}>
+          <h1 style={{
+            fontSize: '2rem',
+            fontWeight: 'bold',
+            marginBottom: '0.5rem',
+            color: '#2c3e50'
+          }}>
+            🚀 Erstkonfiguration
+          </h1>
+          <p style={{
+            color: '#6c757d',
+            fontSize: '1.1rem',
+            marginBottom: '2rem'
+          }}>
+            Richten Sie Ihren Administrator-Account ein
+          </p>
+        </div>
+
+        {/* Aktueller Schritt Titel und Beschreibung */}
+        <div style={{ textAlign: 'center', marginBottom: '1.5rem' }}>
+          <h2 style={{
+            fontSize: '1.5rem',
+            fontWeight: 'bold',
+            marginBottom: '0.5rem',
+            color: '#2c3e50'
+          }}>
+            {steps[currentStep].title}
+          </h2>
+          {steps[currentStep].subtitle && (
+            <p style={{
+              color: '#6c757d',
+              fontSize: '1rem'
+            }}>
+              {steps[currentStep].subtitle}
+            </p>
+          )}
+        </div>
+
+        {/* Inline Step Indicator */}
+        <StepIndicator />
+
+        {/* Fehleranzeige */}
+        {error && (
+          <div style={{
+            backgroundColor: '#f8d7da',
+            border: '1px solid #f5c6cb',
+            color: '#721c24',
+            padding: '1rem',
+            borderRadius: '6px',
+            marginBottom: '1.5rem'
+          }}>
+            {error}
+          </div>
         )}
 
+        {/* Schritt-Inhalt */}
+        <div style={{ minHeight: '200px' }}>
+          {renderStepContent()}
+        </div>
+
+        {/* Navigations-Buttons */}
         <div style={{
           marginTop: '2rem',
           display: 'flex',
           justifyContent: 'space-between',
           alignItems: 'center'
         }}>
-          {step === 2 && (
           <button
-              onClick={handleBack}
+            onClick={goToPrevStep}
+            disabled={loading || currentStep === 0}
             style={{
               padding: '0.75rem 1.5rem',
-                color: '#6c757d',
-                border: '1px solid #6c757d',
+              color: loading || currentStep === 0 ? '#adb5bd' : '#6c757d',
+              border: `1px solid ${loading || currentStep === 0 ? '#adb5bd' : '#6c757d'}`,
               background: 'none',
               borderRadius: '6px',
-                cursor: 'pointer',
-                fontWeight: '500'
+              cursor: loading || currentStep === 0 ? 'not-allowed' : 'pointer',
+              fontWeight: '500',
+              opacity: loading || currentStep === 0 ? 0.6 : 1
             }}
-              disabled={loading}
           >
             ← Zurück
           </button>
-          )}
 
           <button
-            onClick={handleNext}
+            onClick={goToNextStep}
             disabled={loading}
             style={{
               padding: '0.75rem 2rem',
-              backgroundColor: loading ? '#6c757d' : '#007bff',
+              backgroundColor: loading ? '#6c757d' : '#51258f',
               color: 'white',
               border: 'none',
               borderRadius: '6px',
               cursor: loading ? 'not-allowed' : 'pointer',
               fontWeight: '600',
               fontSize: '1rem',
-              marginLeft: step === 1 ? 'auto' : '0',
               transition: 'background-color 0.3s ease'
             }}
           >
-            {loading ? '⏳ Wird verarbeitet...' : 
-             step === 1 ? 'Weiter →' : 'Setup abschließen'}
+            {getNextButtonText()}
           </button>
         </div>
 
-        {step === 2 && (
+        {/* Zusätzliche Informationen */}
+        {currentStep === 2 && !loading && (
           <div style={{
             marginTop: '1.5rem',
             textAlign: 'center',
             color: '#6c757d',
             fontSize: '0.9rem',
             padding: '1rem',
-            backgroundColor: '#e7f3ff',
-            borderRadius: '6px',
-            border: '1px solid #b6d7e8'
+            backgroundColor: '#f8f9fa',
+            borderRadius: '6px'
           }}>
-            💡 Nach dem erfolgreichen Setup werden Sie zur Anmeldeseite weitergeleitet, 
-            wo Sie sich mit Ihrer automatisch generierten E-Mail anmelden können.
+            Überprüfen Sie Ihre Daten, bevor Sie das Setup abschließen
           </div>
         )}
       </div>

frontend/src/pages/ShiftPlans/ShiftPlanCreate.module.css

@@ -107,7 +107,7 @@
 
 .createButton {
   padding: 10px 20px;
-  background-color: #2ecc71;
+  background-color: #51258f;
   color: white;
   border: none;
   border-radius: 4px;
@@ -116,7 +116,7 @@
 }
 
 .createButton:hover {
-  background-color: #27ae60;
+  background-color: #51258f;
 }
 
 .createButton:disabled {

frontend/src/pages/ShiftPlans/ShiftPlanCreate.tsx

@@ -2,6 +2,8 @@
 import React, { useState, useEffect } from 'react';
 import { useNavigate, useSearchParams } from 'react-router-dom';
 import { shiftPlanService } from '../../services/shiftPlanService';
+import { useNotification } from '../../contexts/NotificationContext';
+import { useBackendValidation } from '../../hooks/useBackendValidation';
 import styles from './ShiftPlanCreate.module.css';
 
 // Interface für Template Presets
@@ -14,6 +16,8 @@ interface TemplatePreset {
 const ShiftPlanCreate: React.FC = () => {
   const navigate = useNavigate();
   const [searchParams] = useSearchParams();
+  const { showNotification } = useNotification();
+  const { executeWithValidation, isSubmitting } = useBackendValidation();
   
   const [planName, setPlanName] = useState('');
   const [startDate, setStartDate] = useState('');
@@ -21,8 +25,6 @@ const ShiftPlanCreate: React.FC = () => {
   const [selectedPreset, setSelectedPreset] = useState('');
   const [presets, setPresets] = useState<TemplatePreset[]>([]);
   const [loading, setLoading] = useState(true);
-  const [error, setError] = useState<string | null>(null);
-  const [success, setSuccess] = useState<string | null>(null);
 
   useEffect(() => {
     loadTemplatePresets();
@@ -42,36 +44,60 @@ const ShiftPlanCreate: React.FC = () => {
       }
     } catch (error) {
       console.error('❌ Fehler beim Laden der Vorlagen-Presets:', error);
-      setError('Vorlagen-Presets konnten nicht geladen werden');
+      showNotification({
+        type: 'error',
+        title: 'Fehler beim Laden',
+        message: 'Vorlagen-Presets konnten nicht geladen werden'
+      });
     } finally {
       setLoading(false);
     }
   };
 
   const handleCreate = async () => {
-    try {
-      // Validierung
+    // Basic frontend validation only
     if (!planName.trim()) {
-        setError('Bitte geben Sie einen Namen für den Schichtplan ein');
+      showNotification({
+        type: 'error',
+        title: 'Fehlende Angaben',
+        message: 'Bitte geben Sie einen Namen für den Schichtplan ein'
+      });
       return;
     }
     if (!startDate) {
-        setError('Bitte wählen Sie ein Startdatum');
+      showNotification({
+        type: 'error',
+        title: 'Fehlende Angaben',
+        message: 'Bitte wählen Sie ein Startdatum'
+      });
       return;
     }
     if (!endDate) {
-        setError('Bitte wählen Sie ein Enddatum');
+      showNotification({
+        type: 'error',
+        title: 'Fehlende Angaben', 
+        message: 'Bitte wählen Sie ein Enddatum'
+      });
       return;
     }
     if (new Date(endDate) < new Date(startDate)) {
-        setError('Das Enddatum muss nach dem Startdatum liegen');
+      showNotification({
+        type: 'error',
+        title: 'Ungültige Daten',
+        message: 'Das Enddatum muss nach dem Startdatum liegen'
+      });
       return;
     }
     if (!selectedPreset) {
-        setError('Bitte wählen Sie eine Vorlage aus');
+      showNotification({
+        type: 'error',
+        title: 'Fehlende Angaben',
+        message: 'Bitte wählen Sie eine Vorlage aus'
+      });
       return;
     }
 
+    await executeWithValidation(async () => {
       console.log('🔄 Erstelle Schichtplan aus Preset...', {
         presetName: selectedPreset,
         name: planName,
@@ -91,16 +117,16 @@ const ShiftPlanCreate: React.FC = () => {
       console.log('✅ Plan erstellt:', createdPlan);
       
       // Erfolgsmeldung und Weiterleitung
-      setSuccess('Schichtplan erfolgreich erstellt!');
+      showNotification({
+        type: 'success',
+        title: 'Erfolg',
+        message: 'Schichtplan erfolgreich erstellt!'
+      });
+      
       setTimeout(() => {
         navigate(`/shift-plans/${createdPlan.id}`);
       }, 1500);
-      
-    } catch (error) {
-      const err = error as Error;
-      console.error('❌ Fehler beim Erstellen des Plans:', err);
-      setError(`Plan konnte nicht erstellt werden: ${err.message}`);
-    } 
+    });
   };
 
   const getSelectedPresetDescription = () => {
@@ -120,23 +146,15 @@ const ShiftPlanCreate: React.FC = () => {
     <div className={styles.container}>
       <div className={styles.header}>
         <h1>Neuen Schichtplan erstellen</h1>
-        <button onClick={() => navigate(-1)} className={styles.backButton}>
+        <button 
+          onClick={() => navigate(-1)} 
+          className={styles.backButton}
+          disabled={isSubmitting}
+        >
           Zurück
         </button>
       </div>
       
-      {error && (
-        <div className={styles.error}>
-          {error}
-        </div>
-      )}
-
-      {success && (
-        <div className={styles.success}>
-          {success}
-        </div>
-      )}
-      
       <div className={styles.form}>
         <div className={styles.formGroup}>
           <label>Plan Name:</label>
@@ -146,6 +164,7 @@ const ShiftPlanCreate: React.FC = () => {
             onChange={(e) => setPlanName(e.target.value)}
             placeholder="z.B. KW 42 2025"
             className={styles.input}
+            disabled={isSubmitting}
           />
         </div>
 
@@ -157,6 +176,7 @@ const ShiftPlanCreate: React.FC = () => {
               value={startDate}
               onChange={(e) => setStartDate(e.target.value)}
               className={styles.input}
+              disabled={isSubmitting}
             />
           </div>
 
@@ -167,6 +187,7 @@ const ShiftPlanCreate: React.FC = () => {
               value={endDate}
               onChange={(e) => setEndDate(e.target.value)}
               className={styles.input}
+              disabled={isSubmitting}
             />
           </div>
         </div>
@@ -177,6 +198,7 @@ const ShiftPlanCreate: React.FC = () => {
             value={selectedPreset} 
             onChange={(e) => setSelectedPreset(e.target.value)}
             className={`${styles.select} ${presets.length === 0 ? styles.empty : ''}`}
+            disabled={isSubmitting}
           >
             <option value="">Bitte wählen...</option>
             {presets.map(preset => (
@@ -203,9 +225,9 @@ const ShiftPlanCreate: React.FC = () => {
           <button 
             onClick={handleCreate} 
             className={styles.createButton} 
-            disabled={!selectedPreset || !planName.trim() || !startDate || !endDate}
+            disabled={isSubmitting || !selectedPreset || !planName.trim() || !startDate || !endDate}
           >
-            Schichtplan erstellen
+            {isSubmitting ? 'Wird erstellt...' : 'Schichtplan erstellen'}
           </button>
         </div>
       </div>

frontend/src/pages/ShiftPlans/ShiftPlanEdit.tsx

@@ -4,11 +4,14 @@ import { useParams, useNavigate } from 'react-router-dom';
 import { shiftPlanService } from '../../services/shiftPlanService';
 import { ShiftPlan, Shift, ScheduledShift } from '../../models/ShiftPlan';
 import { useNotification } from '../../contexts/NotificationContext';
+import { useBackendValidation } from '../../hooks/useBackendValidation';
 
 const ShiftPlanEdit: React.FC = () => {
   const { id } = useParams<{ id: string }>();
   const navigate = useNavigate();
-  const { showNotification } = useNotification();
+  const { showNotification, confirmDialog } = useNotification();
+  const { executeWithValidation, isSubmitting } = useBackendValidation();
+  
   const [shiftPlan, setShiftPlan] = useState<ShiftPlan | null>(null);
   const [loading, setLoading] = useState(true);
   const [editingShift, setEditingShift] = useState<Shift | null>(null);
@@ -24,122 +27,150 @@ const ShiftPlanEdit: React.FC = () => {
 
   const loadShiftPlan = async () => {
     if (!id) return;
+    
+    await executeWithValidation(async () => {
       try {
         const plan = await shiftPlanService.getShiftPlan(id);
         setShiftPlan(plan);
       } catch (error) {
         console.error('Error loading shift plan:', error);
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: 'Der Schichtplan konnte nicht geladen werden.'
-      });
         navigate('/shift-plans');
       } finally {
         setLoading(false);
       }
+    });
   };
 
   const handleUpdateShift = async (shift: Shift) => {
     if (!shiftPlan || !id) return;
     
-    try {
-      // Update logic here
+    await executeWithValidation(async () => {
+      // Update logic here - will be implemented when backend API is available
+      // For now, just simulate success
+      console.log('Updating shift:', shift);
+      
       loadShiftPlan();
       setEditingShift(null);
-    } catch (error) {
-      console.error('Error updating shift:', error);
+      
       showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: 'Die Schicht konnte nicht aktualisiert werden.'
+        type: 'success',
+        title: 'Erfolg',
+        message: 'Schicht wurde erfolgreich aktualisiert.'
+      });
     });
-    }
   };
 
   const handleAddShift = async () => {
     if (!shiftPlan || !id) return;
     
-    if (!newShift.timeSlotId || !newShift.requiredEmployees) {
+    // Basic frontend validation only
+    if (!newShift.timeSlotId) {
       showNotification({
         type: 'error',
-        title: 'Fehler',
-        message: 'Bitte füllen Sie alle Pflichtfelder aus.'
+        title: 'Fehlende Angaben',
+        message: 'Bitte wählen Sie einen Zeit-Slot aus.'
       });
       return;
     }
     
-    try {
-      // Add shift logic here
+    if (!newShift.requiredEmployees || newShift.requiredEmployees < 1) {
+      showNotification({
+        type: 'error',
+        title: 'Fehlende Angaben',
+        message: 'Bitte geben Sie die Anzahl der benötigten Mitarbeiter an.'
+      });
+      return;
+    }
+
+    await executeWithValidation(async () => {
+      // Add shift logic here - will be implemented when backend API is available
+      // For now, just simulate success
+      console.log('Adding shift:', newShift);
+      
       showNotification({
         type: 'success',
         title: 'Erfolg',
         message: 'Neue Schicht wurde hinzugefügt.'
       });
+      
       setNewShift({
         timeSlotId: '',
         dayOfWeek: 1,
         requiredEmployees: 1
       });
       loadShiftPlan();
-    } catch (error) {
-      console.error('Error adding shift:', error);
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: 'Die Schicht konnte nicht hinzugefügt werden.'
     });
-    }
   };
 
   const handleDeleteShift = async (shiftId: string) => {
-    if (!window.confirm('Möchten Sie diese Schicht wirklich löschen?')) {
-      return;
-    }
-
-    try {
-      // Delete logic here
-      loadShiftPlan();
-    } catch (error) {
-      console.error('Error deleting shift:', error);
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: 'Die Schicht konnte nicht gelöscht werden.'
+    const confirmed = await confirmDialog({
+      title: 'Schicht löschen',
+      message: 'Möchten Sie diese Schicht wirklich löschen?',
+      confirmText: 'Löschen',
+      cancelText: 'Abbrechen',
+      type: 'warning'
+    });
+
+    if (!confirmed) return;
+
+    await executeWithValidation(async () => {
+      // Delete logic here - will be implemented when backend API is available
+      // For now, just simulate success
+      console.log('Deleting shift:', shiftId);
+      
+      loadShiftPlan();
+      
+      showNotification({
+        type: 'success',
+        title: 'Erfolg',
+        message: 'Schicht wurde erfolgreich gelöscht.'
+      });
     });
-    }
   };
 
   const handlePublish = async () => {
     if (!shiftPlan || !id) return;
 
-    try {
+    await executeWithValidation(async () => {
       await shiftPlanService.updateShiftPlan(id, {
         ...shiftPlan,
         status: 'published'
       });
+      
       showNotification({
         type: 'success',
         title: 'Erfolg',
         message: 'Schichtplan wurde veröffentlicht.'
       });
+      
       loadShiftPlan();
-    } catch (error) {
-      console.error('Error publishing shift plan:', error);
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: 'Der Schichtplan konnte nicht veröffentlicht werden.'
     });
-    }
   };
 
   if (loading) {
-    return <div>Lade Schichtplan...</div>;
+    return (
+      <div style={{ 
+        textAlign: 'center', 
+        padding: '40px',
+        fontSize: '18px',
+        color: '#666'
+      }}>
+        Lade Schichtplan...
+      </div>
+    );
   }
 
   if (!shiftPlan) {
-    return <div>Schichtplan nicht gefunden</div>;
+    return (
+      <div style={{ 
+        textAlign: 'center', 
+        padding: '40px',
+        fontSize: '18px',
+        color: '#e74c3c'
+      }}>
+        Schichtplan nicht gefunden
+      </div>
+    );
   }
 
   // Group shifts by dayOfWeek
@@ -174,28 +205,32 @@ const ShiftPlanEdit: React.FC = () => {
           {shiftPlan.status === 'draft' && (
             <button
               onClick={handlePublish}
+              disabled={isSubmitting}
               style={{
                 padding: '8px 16px',
                 backgroundColor: '#2ecc71',
                 color: 'white',
                 border: 'none',
                 borderRadius: '4px',
-                cursor: 'pointer',
-                marginRight: '10px'
+                cursor: isSubmitting ? 'not-allowed' : 'pointer',
+                marginRight: '10px',
+                opacity: isSubmitting ? 0.6 : 1
               }}
             >
-              Veröffentlichen
+              {isSubmitting ? 'Wird veröffentlicht...' : 'Veröffentlichen'}
             </button>
           )}
           <button
             onClick={() => navigate('/shift-plans')}
+            disabled={isSubmitting}
             style={{
               padding: '8px 16px',
               backgroundColor: '#95a5a6',
               color: 'white',
               border: 'none',
               borderRadius: '4px',
-              cursor: 'pointer'
+              cursor: isSubmitting ? 'not-allowed' : 'pointer',
+              opacity: isSubmitting ? 0.6 : 1
             }}
           >
             Zurück
@@ -219,6 +254,7 @@ const ShiftPlanEdit: React.FC = () => {
               value={newShift.dayOfWeek}
               onChange={(e) => setNewShift({ ...newShift, dayOfWeek: parseInt(e.target.value) })}
               style={{ width: '100%', padding: '8px', borderRadius: '4px', border: '1px solid #ddd' }}
+              disabled={isSubmitting}
             >
               {daysOfWeek.map(day => (
                 <option key={day.id} value={day.id}>{day.name}</option>
@@ -231,6 +267,7 @@ const ShiftPlanEdit: React.FC = () => {
               value={newShift.timeSlotId}
               onChange={(e) => setNewShift({ ...newShift, timeSlotId: e.target.value })}
               style={{ width: '100%', padding: '8px', borderRadius: '4px', border: '1px solid #ddd' }}
+              disabled={isSubmitting}
             >
               <option value="">Bitte auswählen...</option>
               {shiftPlan.timeSlots.map(slot => (
@@ -246,25 +283,27 @@ const ShiftPlanEdit: React.FC = () => {
               type="number"
               min="1"
               value={newShift.requiredEmployees}
-              onChange={(e) => setNewShift({ ...newShift, requiredEmployees: parseInt(e.target.value) })}
+              onChange={(e) => setNewShift({ ...newShift, requiredEmployees: parseInt(e.target.value) || 1 })}
               style={{ width: '100%', padding: '8px', borderRadius: '4px', border: '1px solid #ddd' }}
+              disabled={isSubmitting}
             />
           </div>
         </div>
         <button
           onClick={handleAddShift}
-          disabled={!newShift.timeSlotId || !newShift.requiredEmployees}
+          disabled={isSubmitting || !newShift.timeSlotId || !newShift.requiredEmployees}
           style={{
             marginTop: '15px',
             padding: '8px 16px',
-            backgroundColor: '#3498db',
+            backgroundColor: isSubmitting ? '#bdc3c7' : '#3498db',
             color: 'white',
             border: 'none',
             borderRadius: '4px',
-            cursor: 'pointer'
+            cursor: isSubmitting ? 'not-allowed' : 'pointer',
+            opacity: (!newShift.timeSlotId || !newShift.requiredEmployees) ? 0.6 : 1
           }}
         >
-          Schicht hinzufügen
+          {isSubmitting ? 'Wird hinzugefügt...' : 'Schicht hinzufügen'}
         </button>
       </div>
 
@@ -300,6 +339,7 @@ const ShiftPlanEdit: React.FC = () => {
                               value={editingShift.timeSlotId}
                               onChange={(e) => setEditingShift({ ...editingShift, timeSlotId: e.target.value })}
                               style={{ width: '100%', padding: '8px', borderRadius: '4px', border: '1px solid #ddd' }}
+                              disabled={isSubmitting}
                             >
                               {shiftPlan.timeSlots.map(slot => (
                                 <option key={slot.id} value={slot.id}>
@@ -314,33 +354,37 @@ const ShiftPlanEdit: React.FC = () => {
                               type="number"
                               min="1"
                               value={editingShift.requiredEmployees}
-                              onChange={(e) => setEditingShift({ ...editingShift, requiredEmployees: parseInt(e.target.value) })}
+                              onChange={(e) => setEditingShift({ ...editingShift, requiredEmployees: parseInt(e.target.value) || 1 })}
                               style={{ width: '100%', padding: '8px', borderRadius: '4px', border: '1px solid #ddd' }}
+                              disabled={isSubmitting}
                             />
                           </div>
                           <div style={{ display: 'flex', gap: '10px', alignItems: 'flex-end' }}>
                             <button
                               onClick={() => handleUpdateShift(editingShift)}
+                              disabled={isSubmitting}
                               style={{
                                 padding: '8px 16px',
-                                backgroundColor: '#2ecc71',
+                                backgroundColor: isSubmitting ? '#bdc3c7' : '#2ecc71',
                                 color: 'white',
                                 border: 'none',
                                 borderRadius: '4px',
-                                cursor: 'pointer'
+                                cursor: isSubmitting ? 'not-allowed' : 'pointer'
                               }}
                             >
-                              Speichern
+                              {isSubmitting ? 'Speichern...' : 'Speichern'}
                             </button>
                             <button
                               onClick={() => setEditingShift(null)}
+                              disabled={isSubmitting}
                               style={{
                                 padding: '8px 16px',
                                 backgroundColor: '#95a5a6',
                                 color: 'white',
                                 border: 'none',
                                 borderRadius: '4px',
-                                cursor: 'pointer'
+                                cursor: isSubmitting ? 'not-allowed' : 'pointer',
+                                opacity: isSubmitting ? 0.6 : 1
                               }}
                             >
                               Abbrechen
@@ -359,27 +403,31 @@ const ShiftPlanEdit: React.FC = () => {
                             <div>
                               <button
                                 onClick={() => setEditingShift(shift)}
+                                disabled={isSubmitting}
                                 style={{
                                   padding: '6px 12px',
-                                  backgroundColor: '#f1c40f',
+                                  backgroundColor: isSubmitting ? '#bdc3c7' : '#f1c40f',
                                   color: 'white',
                                   border: 'none',
                                   borderRadius: '4px',
-                                  cursor: 'pointer',
-                                  marginRight: '8px'
+                                  cursor: isSubmitting ? 'not-allowed' : 'pointer',
+                                  marginRight: '8px',
+                                  opacity: isSubmitting ? 0.6 : 1
                                 }}
                               >
                                 Bearbeiten
                               </button>
                               <button
                                 onClick={() => handleDeleteShift(shift.id)}
+                                disabled={isSubmitting}
                                 style={{
                                   padding: '6px 12px',
-                                  backgroundColor: '#e74c3c',
+                                  backgroundColor: isSubmitting ? '#bdc3c7' : '#e74c3c',
                                   color: 'white',
                                   border: 'none',
                                   borderRadius: '4px',
-                                  cursor: 'pointer'
+                                  cursor: isSubmitting ? 'not-allowed' : 'pointer',
+                                  opacity: isSubmitting ? 0.6 : 1
                                 }}
                               >
                                 Löschen

frontend/src/pages/ShiftPlans/ShiftPlanList.tsx

@@ -5,12 +5,15 @@ import { useAuth } from '../../contexts/AuthContext';
 import { shiftPlanService } from '../../services/shiftPlanService';
 import { ShiftPlan } from '../../models/ShiftPlan';
 import { useNotification } from '../../contexts/NotificationContext';
+import { useBackendValidation } from '../../hooks/useBackendValidation';
 import { formatDate } from '../../utils/foramatters';
 
 const ShiftPlanList: React.FC = () => {
   const { hasRole } = useAuth();
   const navigate = useNavigate();
-  const { showNotification } = useNotification();
+  const { showNotification, confirmDialog } = useNotification();
+  const { executeWithValidation, isSubmitting } = useBackendValidation();
+  
   const [shiftPlans, setShiftPlans] = useState<ShiftPlan[]>([]);
   const [loading, setLoading] = useState(true);
 
@@ -19,46 +22,80 @@ const ShiftPlanList: React.FC = () => {
   }, []);
 
   const loadShiftPlans = async () => {
+    await executeWithValidation(async () => {
       try {
         const plans = await shiftPlanService.getShiftPlans();
         setShiftPlans(plans);
       } catch (error) {
         console.error('Error loading shift plans:', error);
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: 'Die Schichtpläne konnten nicht geladen werden.'
-      });
+        // Error is automatically handled by executeWithValidation
       } finally {
         setLoading(false);
       }
+    });
   };
 
-  const handleDelete = async (id: string) => {
-    if (!window.confirm('Möchten Sie diesen Schichtplan wirklich löschen?')) {
-      return;
-    }
+  const handleDelete = async (id: string, planName: string) => {
+    const confirmed = await confirmDialog({
+      title: 'Schichtplan löschen',
+      message: `Möchten Sie den Schichtplan "${planName}" wirklich löschen? Diese Aktion kann nicht rückgängig gemacht werden.`,
+      confirmText: 'Löschen',
+      cancelText: 'Abbrechen',
+      type: 'warning'
+    });
 
-    try {
+    if (!confirmed) return;
+
+    await executeWithValidation(async () => {
       await shiftPlanService.deleteShiftPlan(id);
+      
       showNotification({
         type: 'success',
         title: 'Erfolg',
         message: 'Der Schichtplan wurde erfolgreich gelöscht.'
       });
+      
       loadShiftPlans();
-    } catch (error) {
-      console.error('Error deleting shift plan:', error);
-      showNotification({
-        type: 'error',
-        title: 'Fehler',
-        message: 'Der Schichtplan konnte nicht gelöscht werden.'
     });
-    }
+  };
+
+  const getStatusBadge = (status: string) => {
+    const config = {
+      draft: { text: 'Entwurf', color: '#f39c12', bgColor: '#fef5e7' },
+      published: { text: 'Veröffentlicht', color: '#27ae60', bgColor: '#d5f4e6' },
+      archived: { text: 'Archiviert', color: '#95a5a6', bgColor: '#f8f9fa' }
+    };
+
+    const statusConfig = config[status as keyof typeof config] || config.draft;
+
+    return (
+      <span
+        style={{
+          backgroundColor: statusConfig.bgColor,
+          color: statusConfig.color,
+          padding: '4px 8px',
+          borderRadius: '12px',
+          fontSize: '12px',
+          fontWeight: 'bold',
+          display: 'inline-block'
+        }}
+      >
+        {statusConfig.text}
+      </span>
+    );
   };
 
   if (loading) {
-    return <div>Lade Schichtpläne...</div>;
+    return (
+      <div style={{ 
+        textAlign: 'center', 
+        padding: '40px',
+        fontSize: '18px',
+        color: '#666'
+      }}>
+        Lade Schichtpläne...
+      </div>
+    );
   }
 
   return (
@@ -97,6 +134,21 @@ const ShiftPlanList: React.FC = () => {
           <div style={{ fontSize: '48px', marginBottom: '20px' }}>📋</div>
           <h3>Keine Schichtpläne vorhanden</h3>
           <p>Erstellen Sie Ihren ersten Schichtplan!</p>
+          {hasRole(['admin', 'maintenance']) && (
+            <Link to="/shift-plans/new">
+              <button style={{ 
+                marginTop: '15px',
+                padding: '10px 20px', 
+                backgroundColor: '#51258f', 
+                color: 'white', 
+                border: 'none', 
+                borderRadius: '4px',
+                cursor: 'pointer'
+              }}>
+                Ersten Plan erstellen
+              </button>
+            </Link>
+          )}
         </div>
       ) : (
         <div style={{ display: 'grid', gap: '20px' }}>
@@ -110,35 +162,35 @@ const ShiftPlanList: React.FC = () => {
                 boxShadow: '0 2px 4px rgba(0,0,0,0.1)',
                 display: 'flex',
                 justifyContent: 'space-between',
-                alignItems: 'center'
+                alignItems: 'center',
+                border: plan.status === 'published' ? '2px solid #d5f4e6' : '1px solid #e0e0e0'
               }}
             >
-              <div>
-                <h3 style={{ margin: '0 0 10px 0' }}>{plan.name}</h3>
-                <div style={{ color: '#666', fontSize: '14px' }}>
+              <div style={{ flex: 1 }}>
+                <h3 style={{ margin: '0 0 10px 0', color: '#2c3e50' }}>{plan.name}</h3>
+                <div style={{ color: '#666', fontSize: '14px', marginBottom: '10px' }}>
                   <p style={{ margin: '0' }}>
-                    Zeitraum: {formatDate(plan.startDate)} - {formatDate(plan.endDate)}
+                    <strong>Zeitraum:</strong> {formatDate(plan.startDate)} - {formatDate(plan.endDate)}
                   </p>
                   <p style={{ margin: '5px 0 0 0' }}>
-                    Status: <span style={{
-                      color: plan.status === 'published' ? '#2ecc71' : '#f1c40f',
-                      fontWeight: 'bold'
-                    }}>
-                      {plan.status === 'published' ? 'Veröffentlicht' : 'Entwurf'}
-                    </span>
+                    <strong>Status:</strong> {getStatusBadge(plan.status)}
                   </p>
                 </div>
+                <div style={{ fontSize: '12px', color: '#95a5a6' }}>
+                  Erstellt am: {formatDate(plan.createdAt || '')}
                 </div>
-              <div style={{ display: 'flex', gap: '10px' }}>
+              </div>
+              <div style={{ display: 'flex', gap: '10px', flexWrap: 'wrap' }}>
                 <button
                   onClick={() => navigate(`/shift-plans/${plan.id}`)}
                   style={{
                     padding: '8px 16px',
-                    backgroundColor: '#2ecc71',
+                    backgroundColor: '#3498db',
                     color: 'white',
                     border: 'none',
                     borderRadius: '4px',
-                    cursor: 'pointer'
+                    cursor: 'pointer',
+                    minWidth: '80px'
                   }}
                 >
                   Anzeigen
@@ -149,27 +201,31 @@ const ShiftPlanList: React.FC = () => {
                       onClick={() => navigate(`/shift-plans/${plan.id}/edit`)}
                       style={{
                         padding: '8px 16px',
-                        backgroundColor: '#f1c40f',
+                        backgroundColor: '#f39c12',
                         color: 'white',
                         border: 'none',
                         borderRadius: '4px',
-                        cursor: 'pointer'
+                        cursor: 'pointer',
+                        minWidth: '80px'
                       }}
                     >
                       Bearbeiten
                     </button>
                     <button
-                      onClick={() => handleDelete(plan.id)}
+                      onClick={() => handleDelete(plan.id, plan.name)}
+                      disabled={isSubmitting}
                       style={{
                         padding: '8px 16px',
-                        backgroundColor: '#e74c3c',
+                        backgroundColor: isSubmitting ? '#bdc3c7' : '#e74c3c',
                         color: 'white',
                         border: 'none',
                         borderRadius: '4px',
-                        cursor: 'pointer'
+                        cursor: isSubmitting ? 'not-allowed' : 'pointer',
+                        minWidth: '80px',
+                        opacity: isSubmitting ? 0.6 : 1
                       }}
                     >
-                      Löschen
+                      {isSubmitting ? 'Löscht...' : 'Löschen'}
                     </button>
                   </>
                 )}
@@ -178,6 +234,22 @@ const ShiftPlanList: React.FC = () => {
           ))}
         </div>
       )}
+
+      {/* Info for users without edit permissions */}
+      {!hasRole(['admin', 'maintenance']) && shiftPlans.length > 0 && (
+        <div style={{
+          marginTop: '20px',
+          padding: '15px',
+          backgroundColor: '#e8f4fd',
+          border: '1px solid #b6d7e8',
+          borderRadius: '6px',
+          fontSize: '14px',
+          color: '#2c3e50'
+        }}>
+          <strong>ℹ️ Informationen:</strong> Sie können Schichtpläne nur anzeigen. 
+          Bearbeitungsrechte benötigen Admin- oder Instandhalter-Berechtigungen.
+        </div>
+      )}
     </div>
   );
 };

frontend/src/pages/ShiftPlans/ShiftPlanView.tsx

@@ -1,4 +1,4 @@
-// frontend/src/pages/ShiftPlans/ShiftPlanView.tsx - UPDATED
+// frontend/src/pages/ShiftPlans/ShiftPlanView.tsx
 import React, { useState, useEffect } from 'react';
 import { useParams, useNavigate } from 'react-router-dom';
 import { useAuth } from '../../contexts/AuthContext';
@@ -1118,7 +1118,7 @@ const ShiftPlanView: React.FC = () => {
         </div>
       )}
 
-      {/* Assignment Preview Modal - FIXED CONDITION */}
+      {/* Assignment Preview Modal */}
       {(showAssignmentPreview || assignmentResult) && (
         <div style={{
           position: 'fixed',

frontend/src/react-app-env.d.ts

@@ -1 +0,0 @@
-/// <reference types="react-scripts" />

frontend/src/reportWebVitals.ts

@@ -1,15 +0,0 @@
-import { ReportHandler } from 'web-vitals';
-
-const reportWebVitals = (onPerfEntry?: ReportHandler) => {
-  if (onPerfEntry && onPerfEntry instanceof Function) {
-    import('web-vitals').then(({ getCLS, getFID, getFCP, getLCP, getTTFB }) => {
-      getCLS(onPerfEntry);
-      getFID(onPerfEntry);
-      getFCP(onPerfEntry);
-      getLCP(onPerfEntry);
-      getTTFB(onPerfEntry);
-    });
-  }
-};
-
-export default reportWebVitals;

frontend/src/services/apiClient.ts

@@ -0,0 +1,130 @@
+import { ValidationError, ErrorService } from './errorService';
+
+export class ApiError extends Error {
+  public validationErrors: ValidationError[];
+  public statusCode: number;
+  public originalError?: any;
+
+  constructor(message: string, validationErrors: ValidationError[] = [], statusCode: number = 0, originalError?: any) {
+    super(message);
+    this.name = 'ApiError';
+    this.validationErrors = validationErrors;
+    this.statusCode = statusCode;
+    this.originalError = originalError;
+  }
+}
+
+export class ApiClient {
+  private baseURL: string;
+
+  constructor() {
+    this.baseURL = import.meta.env.VITE_API_URL || '/api';
+  }
+
+  private getAuthHeaders(): HeadersInit {
+    const token = localStorage.getItem('token');
+    return token ? { 'Authorization': `Bearer ${token}` } : {};
+  }
+
+  private async handleApiResponse<T>(response: Response): Promise<T> {
+    if (!response.ok) {
+      let errorData;
+      
+      try {
+        // Try to parse error response as JSON
+        const responseText = await response.text();
+        errorData = responseText ? JSON.parse(responseText) : {};
+      } catch {
+        // If not JSON, create a generic error object
+        errorData = { error: `HTTP ${response.status}: ${response.statusText}` };
+      }
+      
+      // Extract validation errors using your existing ErrorService
+      const validationErrors = ErrorService.extractValidationErrors(errorData);
+
+      if (validationErrors.length > 0) {
+        // Throw error with validationErrors property for useBackendValidation hook
+        throw new ApiError(
+          errorData.error || 'Validation failed',
+          validationErrors,
+          response.status,
+          errorData
+        );
+      }
+
+      // Throw regular error for non-validation errors
+      throw new ApiError(
+        errorData.error || errorData.message || `HTTP error! status: ${response.status}`,
+        [],
+        response.status,
+        errorData
+      );
+    }
+
+    // For successful responses, try to parse as JSON
+    try {
+      const responseText = await response.text();
+      return responseText ? JSON.parse(responseText) : {} as T;
+    } catch (error) {
+      // If response is not JSON but request succeeded (e.g., 204 No Content)
+      return {} as T;
+    }
+  }
+
+  async request<T>(endpoint: string, options: RequestInit = {}): Promise<T> {
+    const url = `${this.baseURL}${endpoint}`;
+    
+    const config: RequestInit = {
+      headers: {
+        'Content-Type': 'application/json',
+        ...this.getAuthHeaders(),
+        ...options.headers,
+      },
+      ...options,
+    };
+
+    try {
+      const response = await fetch(url, config);
+      return await this.handleApiResponse<T>(response);
+    } catch (error) {
+      // Re-throw the error to be caught by useBackendValidation
+      if (error instanceof ApiError) {
+        throw error;
+      }
+      
+      // Wrap non-ApiError errors
+      throw new ApiError(
+        error instanceof Error ? error.message : 'Unknown error occurred',
+        [],
+        0,
+        error
+      );
+    }
+  }
+
+  // Standardized HTTP methods
+  get = <T>(endpoint: string) => this.request<T>(endpoint);
+  
+  post = <T>(endpoint: string, data?: any) => 
+    this.request<T>(endpoint, { 
+      method: 'POST', 
+      body: data ? JSON.stringify(data) : undefined 
+    });
+  
+  put = <T>(endpoint: string, data?: any) => 
+    this.request<T>(endpoint, { 
+      method: 'PUT', 
+      body: data ? JSON.stringify(data) : undefined 
+    });
+  
+  patch = <T>(endpoint: string, data?: any) => 
+    this.request<T>(endpoint, { 
+      method: 'PATCH', 
+      body: data ? JSON.stringify(data) : undefined 
+    });
+  
+  delete = <T>(endpoint: string) => 
+    this.request<T>(endpoint, { method: 'DELETE' });
+}
+
+export const apiClient = new ApiClient();

frontend/src/services/authService.ts

@@ -1,6 +1,5 @@
-// frontend/src/services/authService.ts
 import { Employee } from '../models/Employee';
-const API_BASE = process.env.REACT_APP_API_BASE_URL || '/api';
+import { apiClient } from './apiClient';
 
 export interface LoginRequest {
   email: string;
@@ -24,37 +23,15 @@ class AuthService {
   private token: string | null = null;
 
   async login(credentials: LoginRequest): Promise<AuthResponse> {
-    const response = await fetch(`${API_BASE}/auth/login`, {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify(credentials)
-    });
-
-    if (!response.ok) {
-      const errorData = await response.json();
-      throw new Error(errorData.error || 'Login fehlgeschlagen');
-    }
-
-    const data: AuthResponse = await response.json();
+    const data = await apiClient.post<AuthResponse>('/auth/login', credentials);
     this.token = data.token;
     localStorage.setItem('token', data.token);
     localStorage.setItem('employee', JSON.stringify(data.employee));
-    
     return data;
   }
 
   async register(userData: RegisterRequest): Promise<AuthResponse> {
-    const response = await fetch(`${API_BASE}/employees`, {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify(userData)
-    });
-
-    if (!response.ok) {
-      const errorData = await response.json();
-      throw new Error(errorData.error || 'Registrierung fehlgeschlagen');
-    }
-
+    await apiClient.post('/employees', userData);
     return this.login({
       email: userData.email,
       password: userData.password
@@ -68,34 +45,23 @@ class AuthService {
 
   async fetchCurrentEmployee(): Promise<Employee | null> {
     const token = this.getToken();
-    if (!token) {
-      return null;
-    }
+    if (!token) return null;
 
     try {
-      const response = await fetch(`${API_BASE}/auth/me`, {
-        headers: {
-          'Authorization': `Bearer ${token}`
-        }
-      });
-
-      if (response.ok) {
-        const data = await response.json();
-        const user = data.user;
-        localStorage.setItem('user', JSON.stringify(user));
-        return user;
-      }
+      const data = await apiClient.get<{ user: Employee }>('/auth/me');
+      localStorage.setItem('user', JSON.stringify(data.user));
+      return data.user;
     } catch (error) {
       console.error('Error fetching current user:', error);
-    }
-
       return null;
     }
+  }
 
   logout(): void {
     this.token = null;
     localStorage.removeItem('token');
     localStorage.removeItem('user');
+    localStorage.removeItem('employee');
   }
 
   getToken(): string | null {

frontend/src/services/employeeService.ts

@@ -1,146 +1,58 @@
-// frontend/src/services/employeeService.ts
 import { Employee, CreateEmployeeRequest, UpdateEmployeeRequest, EmployeeAvailability } from '../models/Employee';
-
-const API_BASE_URL = '/api';
-
-const getAuthHeaders = () => {
-  const token = localStorage.getItem('token');
-  return {
-    'Content-Type': 'application/json',
-    'Authorization': `Bearer ${token}`
-  };
-};
+import { apiClient } from './apiClient';
 
 export class EmployeeService {
   async getEmployees(includeInactive: boolean = false): Promise<Employee[]> {
     console.log('🔄 Fetching employees from API...');
 
-    const token = localStorage.getItem('token');
-    console.log('🔑 Token exists:', !!token);
-    
-    const response = await fetch(`${API_BASE_URL}/employees?includeInactive=${includeInactive}`, {
-      headers: getAuthHeaders(),
-    });
-    
-    console.log('📡 Response status:', response.status);
-    
-    if (!response.ok) {
-      const errorText = await response.text();
-      console.error('❌ API Error:', errorText);
-      throw new Error('Failed to fetch employees');
-    }
-    
-    const employees = await response.json();
+    try {
+      const employees = await apiClient.get<Employee[]>(`/employees?includeInactive=${includeInactive}`);
       console.log('✅ Employees received:', employees.length);
-    
       return employees;
+    } catch (error) {
+      console.error('❌ Error fetching employees:', error);
+      throw error; // Let useBackendValidation handle this
+    }
   }
 
   async getEmployee(id: string): Promise<Employee> {
-    const response = await fetch(`${API_BASE_URL}/employees/${id}`, {
-      headers: getAuthHeaders(),
-    });
-    
-    if (!response.ok) {
-      throw new Error('Failed to fetch employee');
-    }
-    
-    return response.json();
+    return apiClient.get<Employee>(`/employees/${id}`);
   }
 
   async createEmployee(employee: CreateEmployeeRequest): Promise<Employee> {
-    const response = await fetch(`${API_BASE_URL}/employees`, {
-      method: 'POST',
-      headers: getAuthHeaders(),
-      body: JSON.stringify(employee),
-    });
-    
-    if (!response.ok) {
-      const error = await response.json();
-      throw new Error(error.error || 'Failed to create employee');
-    }
-    
-    return response.json();
+    return apiClient.post<Employee>('/employees', employee);
   }
 
   async updateEmployee(id: string, employee: UpdateEmployeeRequest): Promise<Employee> {
-    const response = await fetch(`${API_BASE_URL}/employees/${id}`, {
-      method: 'PUT',
-      headers: getAuthHeaders(),
-      body: JSON.stringify(employee),
-    });
-    
-    if (!response.ok) {
-      const error = await response.json();
-      throw new Error(error.error || 'Failed to update employee');
-    }
-    
-    return response.json();
+    return apiClient.put<Employee>(`/employees/${id}`, employee);
   }
 
   async deleteEmployee(id: string): Promise<void> {
-    const response = await fetch(`${API_BASE_URL}/employees/${id}`, {
-      method: 'DELETE',
-      headers: getAuthHeaders(),
-    });
-    
-    if (!response.ok) {
-      const error = await response.json();
-      throw new Error(error.error || 'Failed to delete employee');
-    }
+    await apiClient.delete(`/employees/${id}`);
   }
 
   async getAvailabilities(employeeId: string): Promise<EmployeeAvailability[]> {
-    const response = await fetch(`${API_BASE_URL}/employees/${employeeId}/availabilities`, {
-      headers: getAuthHeaders(),
-    });
-    
-    if (!response.ok) {
-      throw new Error('Failed to fetch availabilities');
+    return apiClient.get<EmployeeAvailability[]>(`/employees/${employeeId}/availabilities`);
   }
 
-    return response.json();
-  }
-
-  async updateAvailabilities(employeeId: string, data: { planId: string, availabilities: Omit<EmployeeAvailability, 'id' | 'employeeId'>[] }): Promise<EmployeeAvailability[]> {
+  async updateAvailabilities(
+    employeeId: string, 
+    data: { planId: string, availabilities: Omit<EmployeeAvailability, 'id' | 'employeeId'>[] }
+  ): Promise<EmployeeAvailability[]> {
     console.log('🔄 Updating availabilities for employee:', employeeId);
-    const response = await fetch(`${API_BASE_URL}/employees/${employeeId}/availabilities`, {
-      method: 'PUT',
-      headers: getAuthHeaders(),
-      body: JSON.stringify(data),
-    });
-    
-    if (!response.ok) {
-      const error = await response.json();
-      throw new Error(error.error || 'Failed to update availabilities');
+    return apiClient.put<EmployeeAvailability[]>(`/employees/${employeeId}/availabilities`, data);
   }
 
-    return response.json();
-  }
-
-  async changePassword(id: string, data: { currentPassword: string, newPassword: string }): Promise<void> {
-    const response = await fetch(`${API_BASE_URL}/employees/${id}/password`, {
-      method: 'PUT',
-      headers: getAuthHeaders(),
-      body: JSON.stringify(data),
-    });
-    
-    if (!response.ok) {
-      const error = await response.json();
-      throw new Error(error.error || 'Failed to change password');
-    }
+  async changePassword(
+    id: string, 
+    data: { currentPassword: string, newPassword: string, confirmPassword: string }
+  ): Promise<void> {
+    return apiClient.put<void>(`/employees/${id}/password`, data);
   }
 
   async updateLastLogin(employeeId: string): Promise<void> {
     try {
-      const response = await fetch(`${API_BASE_URL}/employees/${employeeId}/last-login`, {
-        method: 'PATCH',
-        headers: getAuthHeaders(),
-      });
-
-      if (!response.ok) {
-        throw new Error('Failed to update last login');
-      }
+      await apiClient.patch(`/employees/${employeeId}/last-login`);
     } catch (error) {
       console.error('Error updating last login:', error);
       throw error;

frontend/src/services/errorService.ts

@@ -0,0 +1,38 @@
+// frontend/src/services/errorService.ts
+export interface ValidationError {
+  field: string;
+  message: string;
+  value?: any;
+}
+
+export interface ApiError {
+  error: string;
+  details?: ValidationError[];
+  message?: string;
+}
+
+export class ErrorService {
+  static extractValidationErrors(error: any): ValidationError[] {
+    if (error?.details && Array.isArray(error.details)) {
+      return error.details;
+    }
+    
+    // Fallback for different error formats
+    if (error.message && typeof error.message === 'string') {
+      return [{ field: 'general', message: error.message }];
+    }
+    
+    return [{ field: 'general', message: 'An unknown error occurred' }];
+  }
+
+  static getFieldErrors(errors: ValidationError[], fieldName: string): string[] {
+    return errors
+      .filter(error => error.field === fieldName)
+      .map(error => error.message);
+  }
+
+  static getFirstFieldError(errors: ValidationError[], fieldName: string): string | null {
+    const fieldErrors = this.getFieldErrors(errors, fieldName);
+    return fieldErrors.length > 0 ? fieldErrors[0] : null;
+  }
+}

frontend/src/services/scheduling/useScheduling.ts

@@ -1,71 +0,0 @@
-import { useState, useCallback } from 'react';
-import { ScheduleRequest, ScheduleResult } from '../../models/scheduling';
-
-export const useScheduling = () => {
-  const [loading, setLoading] = useState(false);
-  const [error, setError] = useState<string | null>(null);
-  const [result, setResult] = useState<ScheduleResult | null>(null);
-  
-  const generateSchedule = useCallback(async (request: ScheduleRequest) => {
-    setLoading(true);
-    setError(null);
-    
-    try {
-      console.log('📤 Sending scheduling request:', {
-        shiftPlan: request.shiftPlan.name,
-        employees: request.employees.length,
-        availabilities: request.availabilities.length,
-        constraints: request.constraints.length
-      });
-
-      const response = await fetch('/api/scheduling/generate-schedule', {
-        method: 'POST',
-        headers: { 
-          'Content-Type': 'application/json',
-        },
-        body: JSON.stringify(request)
-      });
-      
-      if (!response.ok) {
-        const errorText = await response.text();
-        throw new Error(`Scheduling request failed: ${response.status} ${errorText}`);
-      }
-      
-      const data: ScheduleResult = await response.json();
-      
-      console.log('📥 Received scheduling result:', {
-        success: data.success,
-        assignments: Object.keys(data.assignments).length,
-        violations: data.violations.length,
-        processingTime: data.processingTime
-      });
-      
-      setResult(data);
-      return data;
-    } catch (err) {
-      const errorMessage = err instanceof Error ? err.message : 'Unknown scheduling error';
-      console.error('❌ Scheduling error:', errorMessage);
-      setError(errorMessage);
-      throw err;
-    } finally {
-      setLoading(false);
-    }
-  }, []);
-  
-  const reset = useCallback(() => {
-    setLoading(false);
-    setError(null);
-    setResult(null);
-  }, []);
-  
-  return { 
-    generateSchedule, 
-    loading, 
-    error, 
-    result,
-    reset
-  };
-};
-
-// Export for backward compatibility
-export default useScheduling;

frontend/src/services/shiftAssignmentService.ts

@@ -1,65 +1,15 @@
-// frontend/src/services/shiftAssignmentService.ts - WEEKLY PATTERN VERSION
 import { ShiftPlan, ScheduledShift } from '../models/ShiftPlan';
 import { Employee, EmployeeAvailability } from '../models/Employee';
-import { authService } from './authService';
 import { AssignmentResult, ScheduleRequest } from '../models/scheduling';
-
-const API_BASE_URL = '/api';
-
-// Helper function to get auth headers
-const getAuthHeaders = () => {
-  const token = localStorage.getItem('token');
-  return {
-    'Content-Type': 'application/json',
-    ...(token && { 'Authorization': `Bearer ${token}` })
-  };
-};
+import { apiClient } from './apiClient';
 
 export class ShiftAssignmentService {
   async updateScheduledShift(id: string, updates: { assignedEmployees: string[] }): Promise<void> {
     try {
-      //console.log('🔄 Updating scheduled shift via API:', { id, updates });
+      console.log('🔄 Updating scheduled shift via API:', { id, updates });
       
-      const response = await fetch(`${API_BASE_URL}/scheduled-shifts/${id}`, {
-        method: 'PUT',
-        headers: {
-          'Content-Type': 'application/json',
-          ...authService.getAuthHeaders()
-        },
-        body: JSON.stringify(updates)
-      });
-
-      // First, check if we got any response
-      if (!response.ok) {
-        // Try to get error message from response
-        const responseText = await response.text();
-        console.error('❌ Server response:', responseText);
-        
-        let errorMessage = `HTTP ${response.status}: ${response.statusText}`;
-        
-        // Try to parse as JSON if possible
-        try {
-          const errorData = JSON.parse(responseText);
-          errorMessage = errorData.error || errorMessage;
-        } catch (e) {
-          // If not JSON, use the text as is
-          errorMessage = responseText || errorMessage;
-        }
-        
-        throw new Error(errorMessage);
-      }
-
-      // Try to parse successful response
-      const responseText = await response.text();
-      let result;
-      try {
-        result = responseText ? JSON.parse(responseText) : {};
-      } catch (e) {
-        console.warn('⚠️ Response was not JSON, but request succeeded');
-        result = { message: 'Update successful' };
-      }
-      
-      console.log('✅ Scheduled shift updated successfully:', result);
+      await apiClient.put(`/scheduled-shifts/${id}`, updates);
+      console.log('✅ Scheduled shift updated successfully');
       
     } catch (error) {
       console.error('❌ Error updating scheduled shift:', error);
@@ -69,48 +19,16 @@ export class ShiftAssignmentService {
 
   async getScheduledShift(id: string): Promise<any> {
     try {
-      const response = await fetch(`${API_BASE_URL}/scheduled-shifts/${id}`, {
-        headers: {
-          'Authorization': `Bearer ${localStorage.getItem('token')}`
-        }
-      });
-
-      if (!response.ok) {
-        const responseText = await response.text();
-        let errorMessage = `HTTP ${response.status}: ${response.statusText}`;
-        
-        try {
-          const errorData = JSON.parse(responseText);
-          errorMessage = errorData.error || errorMessage;
-        } catch (e) {
-          errorMessage = responseText || errorMessage;
-        }
-        
-        throw new Error(errorMessage);
-      }
-
-      const responseText = await response.text();
-      return responseText ? JSON.parse(responseText) : {};
+      return await apiClient.get(`/scheduled-shifts/${id}`);
     } catch (error) {
       console.error('Error fetching scheduled shift:', error);
       throw error;
     }
   }
 
-  // New method to get all scheduled shifts for a plan
   async getScheduledShiftsForPlan(planId: string): Promise<ScheduledShift[]> {
     try {
-      const response = await fetch(`${API_BASE_URL}/scheduled-shifts/plan/${planId}`, {
-        headers: {
-          'Authorization': `Bearer ${localStorage.getItem('token')}`
-        }
-      });
-
-      if (!response.ok) {
-        throw new Error(`Failed to fetch scheduled shifts: ${response.status}`);
-      }
-
-      const shifts = await response.json();
+      const shifts = await apiClient.get<ScheduledShift[]>(`/scheduled-shifts/plan/${planId}`);
       
       // DEBUG: Check the structure of returned shifts
       console.log('🔍 SCHEDULED SHIFTS STRUCTURE:', shifts.slice(0, 3));
@@ -132,21 +50,7 @@ export class ShiftAssignmentService {
   }
 
   private async callSchedulingAPI(request: ScheduleRequest): Promise<AssignmentResult> {
-    const response = await fetch(`${API_BASE_URL}/scheduling/generate-schedule`, {
-      method: 'POST',
-      headers: {
-          'Content-Type': 'application/json',
-          ...authService.getAuthHeaders()
-        },
-      body: JSON.stringify(request)
-    });
-
-    if (!response.ok) {
-      const errorData = await response.json();
-      throw new Error(errorData.error || 'Scheduling failed');
-    }
-
-    return response.json();
+    return await apiClient.post<AssignmentResult>('/scheduling/generate-schedule', request);
   }
 
   async assignShifts(

frontend/src/services/shiftPlanService.ts

@@ -1,198 +1,114 @@
-// frontend/src/services/shiftPlanService.ts
-import { authService } from './authService';
-import { ShiftPlan, CreateShiftPlanRequest, ScheduledShift, CreateShiftFromTemplateRequest } from '../models/ShiftPlan';
+import { ShiftPlan, CreateShiftPlanRequest } from '../models/ShiftPlan';
 import { TEMPLATE_PRESETS } from '../models/defaults/shiftPlanDefaults';
-
-const API_BASE_URL = '/api/shift-plans';
-
-// Helper function to get auth headers
-const getAuthHeaders = () => {
-  const token = localStorage.getItem('token');
-  return {
-    'Content-Type': 'application/json',
-    ...(token && { 'Authorization': `Bearer ${token}` })
-  };
-};
-
-// Helper function to handle responses
-const handleResponse = async (response: Response) => {
-  if (!response.ok) {
-    const errorData = await response.json().catch(() => ({ error: 'Unknown error' }));
-    throw new Error(errorData.error || `HTTP error! status: ${response.status}`);
-  }
-  return response.json();
-};
+import { apiClient } from './apiClient';
 
 export const shiftPlanService = {
   async getShiftPlans(): Promise<ShiftPlan[]> {
-    const response = await fetch(API_BASE_URL, {
-      headers: {
-        'Content-Type': 'application/json',
-        ...authService.getAuthHeaders()
-      }
-    });
-    
-    if (!response.ok) {
-      if (response.status === 401) {
-        authService.logout();
-        throw new Error('Nicht authorisiert - bitte erneut anmelden');
-      }
-      throw new Error('Fehler beim Laden der Schichtpläne');
-    }
-    
-    const plans = await response.json();
+    try {
+      const plans = await apiClient.get<ShiftPlan[]>('/shift-plans');
       
       // Ensure scheduledShifts is always an array
       return plans.map((plan: any) => ({
         ...plan,
         scheduledShifts: plan.scheduledShifts || []
       }));
+    } catch (error: any) {
+      if (error.statusCode === 401) {
+        // You might want to import and use authService here if needed
+        localStorage.removeItem('token');
+        localStorage.removeItem('employee');
+        throw new Error('Nicht authorisiert - bitte erneut anmelden');
+      }
+      throw new Error('Fehler beim Laden der Schichtpläne');
+    }
   },
 
   async getShiftPlan(id: string): Promise<ShiftPlan> {
-    const response = await fetch(`${API_BASE_URL}/${id}`, {
-      headers: {
-        'Content-Type': 'application/json',
-        ...authService.getAuthHeaders()
-      }
-    });
-    
-    if (!response.ok) {
-      if (response.status === 401) {
-        authService.logout();
+    try {
+      return await apiClient.get<ShiftPlan>(`/shift-plans/${id}`);
+    } catch (error: any) {
+      if (error.statusCode === 401) {
+        localStorage.removeItem('token');
+        localStorage.removeItem('employee');
         throw new Error('Nicht authorisiert - bitte erneut anmelden');
       }
       throw new Error('Schichtplan nicht gefunden');
     }
-    
-    return await response.json();
   },
 
   async createShiftPlan(plan: CreateShiftPlanRequest): Promise<ShiftPlan> {
-    const response = await fetch(API_BASE_URL, {
-      method: 'POST',
-      headers: {
-        'Content-Type': 'application/json',
-        ...authService.getAuthHeaders()
-      },
-      body: JSON.stringify(plan)
-    });
-
-    if (!response.ok) {
-      if (response.status === 401) {
-        authService.logout();
+    try {
+      return await apiClient.post<ShiftPlan>('/shift-plans', plan);
+    } catch (error: any) {
+      if (error.statusCode === 401) {
+        localStorage.removeItem('token');
+        localStorage.removeItem('employee');
         throw new Error('Nicht authorisiert - bitte erneut anmelden');
       }
       throw new Error('Fehler beim Erstellen des Schichtplans');
     }
-
-    return response.json();
   },
 
   async updateShiftPlan(id: string, plan: Partial<ShiftPlan>): Promise<ShiftPlan> {
-    const response = await fetch(`${API_BASE_URL}/${id}`, {
-      method: 'PUT',
-      headers: {
-        'Content-Type': 'application/json',
-        ...authService.getAuthHeaders()
-      },
-      body: JSON.stringify(plan)
-    });
-
-    if (!response.ok) {
-      if (response.status === 401) {
-        authService.logout();
+    try {
+      return await apiClient.put<ShiftPlan>(`/shift-plans/${id}`, plan);
+    } catch (error: any) {
+      if (error.statusCode === 401) {
+        localStorage.removeItem('token');
+        localStorage.removeItem('employee');
         throw new Error('Nicht authorisiert - bitte erneut anmelden');
       }
       throw new Error('Fehler beim Aktualisieren des Schichtplans');
     }
-
-    return response.json();
   },
 
   async deleteShiftPlan(id: string): Promise<void> {
-    const response = await fetch(`${API_BASE_URL}/${id}`, {
-      method: 'DELETE',
-      headers: {
-        'Content-Type': 'application/json',
-        ...authService.getAuthHeaders()
-      }
-    });
-
-    if (!response.ok) {
-      if (response.status === 401) {
-        authService.logout();
+    try {
+      await apiClient.delete(`/shift-plans/${id}`);
+    } catch (error: any) {
+      if (error.statusCode === 401) {
+        localStorage.removeItem('token');
+        localStorage.removeItem('employee');
         throw new Error('Nicht authorisiert - bitte erneut anmelden');
       }
       throw new Error('Fehler beim Löschen des Schichtplans');
     }
   },
 
-  // Get specific template or plan
-  getTemplate: async (id: string): Promise<ShiftPlan> => {
-    const response = await fetch(`${API_BASE_URL}/${id}`, {
-      headers: getAuthHeaders()
-    });
-    return handleResponse(response);
+  async getTemplate(id: string): Promise<ShiftPlan> {
+    return await apiClient.get<ShiftPlan>(`/shift-plans/${id}`);
   },
 
-
   async regenerateScheduledShifts(planId: string): Promise<void> {
     try {
       console.log('🔄 Attempting to regenerate scheduled shifts...');
-        
-        // You'll need to add this API endpoint to your backend
-        const response = await fetch(`${API_BASE_URL}/${planId}/regenerate-shifts`, {
-        method: 'POST',
-        headers: {
-            'Content-Type': 'application/json',
-            'Authorization': `Bearer ${localStorage.getItem('token')}`
-        }
-        });
-
-        if (response.ok) {
+      await apiClient.post(`/shift-plans/${planId}/regenerate-shifts`);
       console.log('✅ Scheduled shifts regenerated');
-        } else {
-        console.error('❌ Failed to regenerate shifts');
-        }
     } catch (error) {
       console.error('❌ Error regenerating shifts:', error);
+      throw error;
     }
   },
 
-  // Create new plan
-  createPlan: async (data: CreateShiftPlanRequest): Promise<ShiftPlan> => {
-    const response = await fetch(`${API_BASE_URL}`, {
-      method: 'POST',
-      headers: getAuthHeaders(),
-      body: JSON.stringify(data),
-    });
-    return handleResponse(response);
+  async createPlan(data: CreateShiftPlanRequest): Promise<ShiftPlan> {
+    return await apiClient.post<ShiftPlan>('/shift-plans', data);
   },
 
-  createFromPreset: async (data: {
+  async createFromPreset(data: {
     presetName: string;
     name: string;
     startDate: string;
     endDate: string;
     isTemplate?: boolean;
-  }): Promise<ShiftPlan> => {
-    const response = await fetch(`${API_BASE_URL}/from-preset`, {
-      method: 'POST',
-      headers: getAuthHeaders(),
-      body: JSON.stringify(data),
-    });
-    
-    if (!response.ok) {
-      const errorData = await response.json().catch(() => ({ error: 'Unknown error' }));
-      throw new Error(errorData.error || `HTTP error! status: ${response.status}`);
+  }): Promise<ShiftPlan> {
+    try {
+      return await apiClient.post<ShiftPlan>('/shift-plans/from-preset', data);
+    } catch (error: any) {
+      throw new Error(error.message || `HTTP error! status: ${error.statusCode}`);
     }
-    
-    return response.json();
   },
 
-  getTemplatePresets: async (): Promise<{name: string, label: string, description: string}[]> => {
-    // name = label
+  async getTemplatePresets(): Promise<{name: string, label: string, description: string}[]> {
     return Object.entries(TEMPLATE_PRESETS).map(([key, preset]) => ({
       name: key,
       label: preset.name,
@@ -203,22 +119,8 @@ export const shiftPlanService = {
   async clearAssignments(planId: string): Promise<void> {
     try {
       console.log('🔄 Clearing assignments for plan:', planId);
-      
-      const response = await fetch(`${API_BASE_URL}/${planId}/clear-assignments`, {
-        method: 'POST',
-        headers: {
-          'Content-Type': 'application/json',
-          ...authService.getAuthHeaders()
-        }
-      });
-
-      if (!response.ok) {
-        const errorData = await response.json().catch(() => ({ error: 'Unknown error' }));
-        throw new Error(errorData.error || `Failed to clear assignments: ${response.status}`);
-      }
-
+      await apiClient.post(`/shift-plans/${planId}/clear-assignments`);
       console.log('✅ Assignments cleared successfully');
-      
     } catch (error) {
       console.error('❌ Error clearing assignments:', error);
       throw error;

frontend/src/setupTests.ts

@@ -1,5 +0,0 @@
-// jest-dom adds custom jest matchers for asserting on DOM nodes.
-// allows you to do things like:
-// expect(element).toHaveTextContent(/react/i)
-// learn more: https://github.com/testing-library/jest-dom
-import '@testing-library/jest-dom';

frontend/src/vite-env.d.ts

@@ -0,0 +1,12 @@
+/// <reference types="vite/client" />
+
+// Define types for environment variables
+interface ImportMetaEnv {
+  readonly VITE_APP_TITLE: string
+  readonly ENABLE_PRO: string
+  // more env variables...
+}
+
+interface ImportMeta {
+  readonly env: ImportMetaEnv
+}

frontend/tsconfig.json

@@ -1,27 +1,38 @@
 {
   "compilerOptions": {
-    "target": "es5",
-    "lib": [
-      "dom",
-      "dom.iterable",
-      "esnext"
-    ],
-    "allowJs": true,
-    "esModuleInterop": true,
-    "allowSyntheticDefaultImports": true,
-    "strict": true,
-    "forceConsistentCasingInFileNames": true,
-    "noFallthroughCasesInSwitch": true,
-    "module": "esnext",
-    "moduleResolution": "node",
+    "target": "ES2020",
+    "useDefineForClassFields": true,
+    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "skipLibCheck": true,
+    //"ignoreDeprecations": "6.0",
+
+    /* Bundler mode */
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
     "resolveJsonModule": true,
     "isolatedModules": true,
     "noEmit": true,
-    "ignoreDeprecations": "6.0",
     "jsx": "react-jsx",
-    "downlevelIteration": true
-  },
-  "include": [
-    "src"
-  ]
+
+    /* Linting */
+    "strict": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "noFallthroughCasesInSwitch": true,
+
+    /* Path mapping (modern approach) */
+    "paths": {
+      "@/*": ["./src/*"],
+      "@/components/*": ["./src/components/*"],
+      "@/pages/*": ["./src/pages/*"],
+      "@/contexts/*": ["./src/contexts/*"],
+      "@/utils/*": ["./src/utils/*"],
+      "@/services/*": ["./src/services/*"],
+      "@/models/*": ["./src/models/*"],
+      "@/design/*": ["./src/design/*"]
+    }
+  },
+  "include": ["src"],
+  "references": [{ "path": "./tsconfig.node.json" }]
 }

frontend/tsconfig.node.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "composite": true,
+    "skipLibCheck": true,
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "allowSyntheticDefaultImports": true
+  },
+  "include": ["vite.config.ts"]
+}

frontend/vite.config.ts

@@ -0,0 +1,79 @@
+import { defineConfig, loadEnv } from 'vite'
+import react from '@vitejs/plugin-react'
+import { resolve } from 'path'
+
+export default defineConfig(({ mode }) => {
+  const isProduction = mode === 'production'
+  const env = loadEnv(mode, process.cwd(), '')
+
+  return {
+    plugins: [react()],
+
+    // Development proxy
+    server: isProduction ? undefined : {
+      port: 3003,
+      host: true,
+      proxy: {
+        '/api': {
+          target: 'http://localhost:3002',
+          changeOrigin: true,
+          secure: false,
+        }
+      }
+    },
+
+    // Production build optimized for Express serving
+    build: {
+      outDir: 'dist',
+      sourcemap: false, // Disable in production
+      minify: 'terser',
+      
+      // Bundle optimization
+      rollupOptions: {
+        output: {
+          // Efficient chunking
+          manualChunks: {
+            vendor: ['react', 'react-dom', 'react-router-dom'],
+            utils: ['date-fns']
+          },
+          // Cache-friendly naming
+          chunkFileNames: 'assets/[name]-[hash].js',
+          entryFileNames: 'assets/[name]-[hash].js',
+          assetFileNames: 'assets/[name]-[hash].[ext]',
+        }
+      },
+      
+      // Performance optimizations
+      terserOptions: {
+        compress: {
+          drop_console: true,
+          drop_debugger: true,
+          pure_funcs: ['console.log', 'console.debug']
+        }
+      },
+      
+      // Reduce chunking overhead
+      chunkSizeWarningLimit: 800
+    },
+
+    resolve: {
+      alias: {
+        '@': resolve(__dirname, './src'),
+        '@/components': resolve(__dirname, './src/components'),
+        '@/pages': resolve(__dirname, './src/pages'),
+        '@/contexts': resolve(__dirname, './src/contexts'),
+        '@/models': resolve(__dirname, './src/models'),
+        '@/utils': resolve(__dirname, './src/utils'),
+        '@/services': resolve(__dirname, './src/services'),
+        '@/design': resolve(__dirname, './src/design')
+      }
+    },
+
+    // Environment variables
+    define: {
+      'import.meta.env.VITE_API_URL': JSON.stringify(isProduction ? '/api' : '/api'),
+      'import.meta.env.ENABLE_PRO': JSON.stringify(env.ENABLE_PRO || 'false'),
+      'import.meta.env.NODE_ENV': JSON.stringify(mode)
+    }
+  }
+})