Add weblink playlist support and fix offline playback recursion

- get_playlists_v2: pass through weblink items without download, preserve type
- main.py: render weblink items fullscreen via Chromium kiosk overlay with cleanup on next/pause/stop
- main.py: fix unbounded recursion when playlist media is missing/invalid by scheduling retries via Clock (keeps standard playlist cycling offline)
- docs: add PLAYER_WEBLINK_INTEGRATION.md

src/get_playlists_v2.py

@@ -243,6 +243,20 @@ def download_media_files(playlist, media_dir, ssl_manager=None, server_url=None)
         file_name = media.get('file_name', '')
         file_url = media.get('url', '')
         duration = media.get('duration', 10)
+        item_type = media.get('type', '')
+
+        # Web-link items have no file to download — pass the link through unchanged.
+        if item_type == 'weblink':
+            logger.info(f"🔗 Web link item (no download): {file_url}")
+            updated_playlist.append({
+                'file_name': file_name,
+                'type': 'weblink',
+                'url': file_url,  # keep the original web address (not a local path)
+                'duration': duration,
+                'edit_on_player': False,
+            })
+            continue
+
         local_path = os.path.join(media_dir, file_name)
         
         logger.info(f"📥 Preparing to download {file_name}...")
@@ -307,6 +321,7 @@ def download_media_files(playlist, media_dir, ssl_manager=None, server_url=None)
         # (it might already exist or be available later)
         updated_media = {
             'file_name': file_name,
+            'type': item_type,  # Preserve media type (image/video/...)
             'url': os.path.relpath(local_path, os.path.dirname(media_dir)),
             'duration': duration,
             'edit_on_player': media.get('edit_on_player', False)  # Preserve edit_on_player flag