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/cast_logic.py

@@ -17,16 +17,48 @@ class CastManager:
         self._lock = threading.Lock()
         self._discover_thread = None
         self.browser = None
+        self.zconf = None
+        self.found_devices = {}
 
     def discover(self, timeout=5):
-        logger.info("Discovering Chromecasts...")
-        chromecasts, browser = pychromecast.get_chromecasts(timeout=timeout)
-        self.browser = browser
-        if chromecasts:
-            # For simplicity, pick the first one found or allow selection later
-            # In a real scenario, we might want to target a specific name
-            self.chromecast = chromecasts[0]
-            logger.info(f"Found Chromecast: {self.chromecast.name}")
+        logger.info("Starting Chromecast discovery...")
+        import zeroconf
+        from pychromecast.discovery import CastBrowser, SimpleCastListener
+        from .utils import get_host_ip
+
+        if not self.browser:
+            try:
+                ip = get_host_ip()
+                logger.info(f"Binding zeroconf to IP: {ip} (unicast mode)")
+                # unicast=True prevents binding to port 5353, avoiding conflict with Avahi
+                self.zconf = zeroconf.Zeroconf(interfaces=[ip], unicast=True)
+            except Exception as e:
+                logger.error(f"Zeroconf init failed: {e}")
+                self.zconf = zeroconf.Zeroconf(unicast=True)
+            
+            self.found_devices = {}
+            
+            def add_callback(uuid, service):
+                cast_info = self.browser.devices[uuid]
+                cast = pychromecast.get_chromecast_from_cast_info(cast_info, self.zconf)
+                self.found_devices[cast.name] = cast
+                logger.info(f"Discovered Chromecast: {cast.name}")
+
+            listener = SimpleCastListener(add_callback=add_callback)
+            self.browser = CastBrowser(listener, zeroconf_instance=self.zconf)
+            self.browser.start_discovery()
+
+        # Wait up to timeout seconds to find at least one
+        start_time = time.time()
+        while time.time() - start_time < timeout:
+            if self.found_devices:
+                break
+            time.sleep(0.1)
+
+        if self.found_devices:
+            # Pick the first one
+            self.chromecast = list(self.found_devices.values())[0]
+            logger.info(f"Selected Chromecast: {self.chromecast.name}")
             self.chromecast.wait()
             self.mc = self.chromecast.media_controller
             self.mc.register_status_listener(self)