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>

scripts/dev-run.sh

@@ -13,4 +13,8 @@ if [ -n "${pids}" ]; then
 fi
 
 cd "$ROOT_DIR/src"
-exec python main.py
+exec env LED_CONTROLLER_LIVE_RELOAD=1 python -m uvicorn fastapi_app:app \
+  --host 0.0.0.0 --port "$PORT" --reload --reload-dir . \
+  --reload-include '**/*.html' --reload-include '**/*.css' --reload-include '**/*.js' \
+  --reload-exclude '**/db/**' --reload-exclude '**/settings.json' \
+  --reload-exclude '**/settings.json.*'