added Validation rules

backend/src/middleware/Validation/Authentication.md

@@ -0,0 +1,16 @@
+## Authentication
+
+### \[ACTION: login\]
+* Requires valid email and password format
+* Server validates credentials before issuing token
+* Token and employee data stored in localStorage upon success
+
+### \[ACTION: register\]
+* Requires email, password, and name
+* 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