added init files

backend/src/database/schema.sql

@@ -0,0 +1,24 @@
+-- Zusätzliche Tabellen für shift_plans
+CREATE TABLE IF NOT EXISTS shift_plans (
+  id TEXT PRIMARY KEY,
+  name TEXT NOT NULL,
+  start_date TEXT NOT NULL,
+  end_date TEXT NOT NULL,
+  template_id TEXT,
+  status TEXT CHECK(status IN ('draft', 'published')) DEFAULT 'draft',
+  created_by TEXT NOT NULL,
+  created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+  FOREIGN KEY (created_by) REFERENCES users(id),
+  FOREIGN KEY (template_id) REFERENCES shift_templates(id)
+);
+
+CREATE TABLE IF NOT EXISTS assigned_shifts (
+  id TEXT PRIMARY KEY,
+  shift_plan_id TEXT NOT NULL,
+  date TEXT NOT NULL,
+  start_time TEXT NOT NULL,
+  end_time TEXT NOT NULL,
+  required_employees INTEGER DEFAULT 1,
+  assigned_employees TEXT DEFAULT '[]', -- JSON array of user IDs
+  FOREIGN KEY (shift_plan_id) REFERENCES shift_plans(id) ON DELETE CASCADE
+);