feat(auth): implement user plans and credits system with related endpoints

app/services/decorators.py

@@ -32,6 +32,8 @@ def get_user_from_jwt() -> dict[str, Any] | None:
             "is_active": is_active,
             "provider": claims.get("provider", "unknown"),
             "providers": claims.get("providers", []),
+            "plan": claims.get("plan"),
+            "credits": claims.get("credits"),
         }
     except Exception:
         return None
@@ -64,6 +66,8 @@ def get_user_from_api_token() -> dict[str, Any] | None:
                 "provider": "api_token",
                 "providers": [p.provider for p in user.oauth_providers]
                 + ["api_token"],
+                "plan": user.plan.to_dict() if user.plan else None,
+                "credits": user.credits,
             }
 
         return None
@@ -126,3 +130,45 @@ def require_role(required_role: str):
         return wrapper
 
     return decorator
+
+
+def require_credits(credits_needed: int):
+    """Decorator to require and deduct credits for routes."""
+    def decorator(f):
+        @wraps(f)
+        def wrapper(*args, **kwargs):
+            from app.models.user import User
+            from app.database import db
+            
+            # First check authentication
+            user_data = get_current_user()
+            if not user_data:
+                return jsonify({"error": "Authentication required"}), 401
+            
+            # Get the actual user from database to check/update credits
+            user = User.query.get(int(user_data["id"]))
+            if not user or not user.is_active:
+                return jsonify({"error": "User not found or inactive"}), 401
+            
+            # Check if user has enough credits
+            if user.credits < credits_needed:
+                return (
+                    jsonify(
+                        {
+                            "error": f"Insufficient credits. Required: {credits_needed}, Available: {user.credits}"
+                        }
+                    ),
+                    402,  # Payment Required status code
+                )
+            
+            # Deduct credits
+            user.credits -= credits_needed
+            db.session.commit()
+            
+            # Execute the function
+            result = f(*args, **kwargs)
+            
+            return result
+        
+        return wrapper
+    return decorator