- Remove unused _get_pypi_upstream_sources_cached function (never called)
- Remove unused CacheService import and get_cache helper
- Remove unused cache parameter from pypi_download_file
- Fix asyncio.get_event_loop() deprecation - use get_running_loop()
- Note: The caching implementation was incomplete but the other
performance improvements (connection pooling, batch DB ops) remain
Add HttpClientManager class for managing httpx.AsyncClient pools with
FastAPI lifespan integration. Features include:
- Default shared connection pool for general requests
- Configurable max connections, keep-alive, and timeouts
- Dedicated thread pool for blocking I/O operations
- Graceful startup/shutdown lifecycle management
- Per-upstream client isolation support (for future use)
Includes comprehensive unit tests covering initialization, startup,
shutdown, client retrieval, blocking operations, idempotency, and
error handling.
