phase 16: fix ruff lint - move imports to top of file

services/api/app.py

@@ -14,14 +14,16 @@ from __future__ import annotations
 
 import json
 import logging
+import time as _time
 from contextlib import asynccontextmanager
 from datetime import datetime, timezone
 from typing import Any, Optional
 
 import asyncpg
+import httpx
 from fastapi import FastAPI, HTTPException, Query, Request
-from pydantic import BaseModel
 from prometheus_client import CONTENT_TYPE_LATEST, generate_latest
+from pydantic import BaseModel
 from starlette.middleware.base import BaseHTTPMiddleware
 from starlette.responses import Response
 
@@ -1512,9 +1514,6 @@ async def get_source_coverage_gaps():
 # Analytics: Trino SQL Proxy  (Requirement 10.1, 10.3, 13.7)
 # ---------------------------------------------------------------------------
 
-import time as _time
-import httpx
-
 
 @app.post("/api/analytics/query")
 async def analytics_query(body: dict[str, Any]):