feat: add unified linting scripts and git hooks for code quality enforcement

- Introduced `lint` and `lint-fix` applications in `flake.nix` for unified linting of backend (Python) and frontend (TypeScript/Svelte) code.
- Added `scripts/lint.sh` for manual linting execution.
- Created `scripts/install-hooks.sh` to set up git hooks for automatic linting before commits and optional tests before pushes.
- Updated `README.md` with instructions for using the new linting features and git hooks.

backend/app/api/auth.py

@@ -1,4 +1,5 @@
 """Authentication endpoints."""
+
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.orm import Session
 
@@ -16,37 +17,31 @@ router = APIRouter(prefix="/auth", tags=["auth"])
 def register_user(user_data: UserCreate, db: Session = Depends(get_db)):
     """
     Register a new user.
-    
+
     Args:
         user_data: User registration data
         db: Database session
-        
+
     Returns:
         Created user information
-        
+
     Raises:
         HTTPException: If email already exists or password is weak
     """
     repo = UserRepository(db)
-    
+
     # Check if email already exists
     if repo.email_exists(user_data.email):
-        raise HTTPException(
-            status_code=status.HTTP_409_CONFLICT,
-            detail="Email already registered"
-        )
-    
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="Email already registered")
+
     # Validate password strength
     is_valid, error_message = validate_password_strength(user_data.password)
     if not is_valid:
-        raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=error_message
-        )
-    
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=error_message)
+
     # Create user
     user = repo.create_user(email=user_data.email, password=user_data.password)
-    
+
     return UserResponse.model_validate(user)
 
 
@@ -54,22 +49,22 @@ def register_user(user_data: UserCreate, db: Session = Depends(get_db)):
 def login_user(login_data: UserLogin, db: Session = Depends(get_db)):
     """
     Login user and return JWT token.
-    
+
     Args:
         login_data: Login credentials
         db: Database session
-        
+
     Returns:
         JWT access token and user information
-        
+
     Raises:
         HTTPException: If credentials are invalid
     """
     repo = UserRepository(db)
-    
+
     # Get user by email
     user = repo.get_user_by_email(login_data.email)
-    
+
     # Verify user exists and password is correct
     if not user or not verify_password(login_data.password, user.password_hash):
         raise HTTPException(
@@ -77,34 +72,26 @@ def login_user(login_data: UserLogin, db: Session = Depends(get_db)):
             detail="Incorrect email or password",
             headers={"WWW-Authenticate": "Bearer"},
         )
-    
+
     # Check if user is active
     if not user.is_active:
-        raise HTTPException(
-            status_code=status.HTTP_403_FORBIDDEN,
-            detail="User account is deactivated"
-        )
-    
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="User account is deactivated")
+
     # Create access token
     access_token = create_access_token(user_id=user.id, email=user.email)
-    
-    return TokenResponse(
-        access_token=access_token,
-        token_type="bearer",
-        user=UserResponse.model_validate(user)
-    )
+
+    return TokenResponse(access_token=access_token, token_type="bearer", user=UserResponse.model_validate(user))
 
 
 @router.get("/me", response_model=UserResponse)
 def get_current_user_info(current_user: User = Depends(get_current_user)):
     """
     Get current authenticated user information.
-    
+
     Args:
         current_user: Current authenticated user (from JWT)
-        
+
     Returns:
         Current user information
     """
     return UserResponse.model_validate(current_user)
-