refactor: remove unused import of contextlib from server.py

Author: akschord1

deploy/docker/server.py

@@ -7,7 +7,6 @@
 """
 
 # ── stdlib & 3rd‑party imports ───────────────────────────────
-import contextlib
 from crawler_pool import get_crawler, close_all, janitor
 from crawl4ai import AsyncWebCrawler, BrowserConfig, CrawlerRunConfig
 from auth import create_access_token, get_token_dependency, TokenRequest