refactor(decorators): simplify require_admin decorator by reusing require_role

app/services/decorators.py

@@ -148,22 +148,7 @@ def require_role(required_role: str):
 
 def require_admin(f):
     """Decorator to require admin role for routes."""
-
-    @wraps(f)
-    def wrapper(*args, **kwargs):
-        user = get_current_user()
-        if not user:
-            return jsonify({"error": "Authentication required"}), 401
-
-        if user.get("role") != "admin":
-            return (
-                jsonify({"error": "Access denied. Admin role required"}),
-                403,
-            )
-
-        return f(*args, **kwargs)
-
-    return wrapper
+    return require_role("admin")(f)
 
 
 def require_credits(credits_needed: int):