feat: resolve chromecast discovery conflict and add CI/CD workflow

- Update Zeroconf to unicast mode to resolve port 5353 conflict with avahi-daemon
- Make API and Streamlit ports configurable via environment variables (defaults: 8055, 8505)
- Add Gitea Actions workflow for automated Docker builds and registry pushes
- Refactor Chromecast discovery to use modern CastBrowser API

app/api.py

@@ -5,7 +5,7 @@ from typing import List
 import os
 from .library import scan_library
 from .cast_logic import cast_manager
-from .utils import get_logger, VIDEOS_DIR, THUMBNAILS_DIR, get_host_ip
+from .utils import get_logger, VIDEOS_DIR, THUMBNAILS_DIR, get_host_ip, API_PORT
 
 logger = get_logger(__name__)
 
@@ -25,9 +25,8 @@ async def get_library():
 @app.post("/cast")
 async def start_casting(request: CastRequest, background_tasks: BackgroundTasks):
     host_ip = get_host_ip()
-    # Port is 8000 by default for uvicorn in our setup
-    urls = [f"http://{host_ip}:8000/media/{path}" for path in request.video_paths]
-    
+    urls = [f"http://{host_ip}:{API_PORT}/media/{path}" for path in request.video_paths]
+
     logger.info(f"Received cast request for {len(urls)} videos")
     cast_manager.play_queue(urls)
     return {"status": "started", "queue_len": len(urls)}