refactor(api): migrate server to fastapi and uvicorn

Replace the Microdot-only entrypoint with a CombinedASGI app that
handles FastAPI routes (audio API, websocket, dev live-reload) while
delegating the rest to Microdot. Suppress noisy /__dev/ access logs
during live-reload polling.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/conftest.py

@@ -1,6 +1,8 @@
 from pathlib import Path
 import sys
 
+pytest_plugins = ["api_server"]
+
 PROJECT_ROOT = Path(__file__).resolve().parents[1]
 SRC_PATH = PROJECT_ROOT / "src"
 LIB_PATH = PROJECT_ROOT / "lib"