fix: resolve AttributeError in User model and ensure consistent password handling

- Fixed the `AttributeError: 'User' object has no attribute '_password'` by properly mapping the `_password` attribute to the `password` column in the database.
- Updated the `User` model to ensure passwords are only hashed once during creation and not re-hashed when retrieved or updated.
- Improved the `check_password` method to correctly compare hashed passwords.
- Verified the signup and login flow to ensure consistent behavior

services/UserService/user.py

@@ -1,27 +1,30 @@
 from models.User.user import User, db
-from werkzeug.security import generate_password_hash, check_password_hash
 
 class UserService:
     def create_user(self, username, password):
         if not username or not password:
-            return jsonify({"error": "Username and password are required"}), 400
+            raise ValueError("Username and password are required")
         
         if len(username) < 3 or len(password) < 8:
-            return jsonify({"error": "Username must be at least 3 characters and password must be at least 8 characters."}), 400
-
+            raise ValueError("Username must be at least 3 characters and password must be at least 8 characters.")
         
         existing_user = User.query.filter_by(username=username).first()
         if existing_user:
             raise ValueError("User already exists")
         
-        hashed_password = generate_password_hash(password)
-        new_user = User(username=username, password=hashed_password)
+        new_user = User(username=username, password=password)
         db.session.add(new_user)
         db.session.commit()
         return new_user
 
     def verify_user(self, username, password):
         user = User.query.filter_by(username=username).first()
-        if not user or not user.check_password(password):
+        if not user:
+            print(f"User not found: {username}")
             raise ValueError("Invalid username or password")
+        
+        if not user.check_password(password):
+            raise ValueError("Invalid username or password")
+        
+        print(f"User verified: {username}")
         return user