Fix YouTube iframe: support youtube_api source from Modal proxy

src/app.py

@@ -553,7 +553,8 @@ def play_next_segment():
             print(f"🎵 Preparing music: {track.get('title', 'Unknown')} by {track.get('artist', 'Unknown')}")
             
             # Get streaming URL for YouTube or SoundCloud
-            if track.get("source") == "youtube" and track.get("url"):
+            # Modal proxy returns "youtube_api" as source, so check both
+            if track.get("source") in ["youtube", "youtube_api"] and track.get("url"):
                 try:
                     # Extract YouTube ID
                     youtube_id = track.get("youtube_id", "")
@@ -1095,7 +1096,8 @@ def handle_voice_request(audio_file):
         player_id = f"voice_player_{int(time.time())}"
         timer_config = gr.Timer(value=0, active=False)
         
-        if track.get("source") == "youtube":
+        # Modal proxy returns "youtube_api" as source, so check both
+        if track.get("source") in ["youtube", "youtube_api"]:
             youtube_id = track.get("youtube_id", "")
             if not youtube_id and "v=" in track.get("url", ""):
                 youtube_id = track["url"].split("v=")[-1].split("&")[0]