Release v0.4.0 - HD Thumbnails, YouTube 2024+ Support, and yt-dlp Integration

Major Features:
- HD video thumbnails (hq720.jpg) with automatic fallback to lower qualities
- HD channel avatars (240x240 instead of 88x88)
- YouTube 2024+ lockupViewModel support for channel playlists
- youtubei/v1/browse API integration for channel playlist tabs
- yt-dlp integration for multi-language audio and subtitles

Bug Fixes:
- Fixed undefined `abort` import in playlist.py
- Fixed undefined functions in proto.py (encode_varint, bytes_to_hex, succinct_encode)
- Fixed missing `traceback` import in proto_debug.py
- Fixed blurry playlist thumbnails using default.jpg instead of HD versions
- Fixed channel playlists page using deprecated pbj=1 format

Improvements:
- Automatic thumbnail fallback system (hq720 → sddefault → hqdefault → mqdefault → default)
- JavaScript thumbnail_fallback() handler for 404 errors
- Better thumbnail quality across all pages (watch, channel, playlist, subscriptions)
- Consistent HD avatar display for all channel items
- Settings system automatically adds new settings without breaking user config

Files Modified:
- youtube/watch.py - HD thumbnails for related videos and playlist items
- youtube/channel.py - HD thumbnails for channel playlists, youtubei API integration
- youtube/playlist.py - HD thumbnails, fixed abort import
- youtube/util.py - HD thumbnail URLs, avatar HD upgrade, prefix_url improvements
- youtube/comments.py - HD video thumbnail
- youtube/subscriptions.py - HD thumbnails, fixed abort import
- youtube/yt_data_extract/common.py - lockupViewModel support, extract_lockup_view_model_info()
- youtube/yt_data_extract/everything_else.py - HD playlist thumbnails
- youtube/proto.py - Fixed undefined function references
- youtube/proto_debug.py - Added traceback import
- youtube/static/js/common.js - thumbnail_fallback() handler
- youtube/templates/*.html - Added onerror handlers for thumbnail fallback
- youtube/version.py - Bump to v0.4.0

Technical Details:
- All thumbnail URLs now use hq720.jpg (1280x720) when available
- Fallback handled client-side via JavaScript onerror handler
- Server-side avatar upgrade via regex in util.prefix_url()
- lockupViewModel parser extracts contentType, metadata, and first_video_id
- Channel playlist tabs now use youtubei/v1/browse instead of deprecated pbj=1
- Settings version system ensures backward compatibility

youtube/yt_data_extract/common.py

@@ -226,6 +226,89 @@ def check_missing_keys(object, *key_sequences):
 
     return None
 
+
+def extract_lockup_view_model_info(item, additional_info={}):
+    """Extract info from new lockupViewModel format (YouTube 2024+)"""
+    info = {'error': None}
+
+    content_type = item.get('contentType', '')
+    content_id = item.get('contentId', '')
+
+    # Extract title from metadata
+    metadata = item.get('metadata', {})
+    lockup_metadata = metadata.get('lockupMetadataViewModel', {})
+    title_data = lockup_metadata.get('title', {})
+    info['title'] = title_data.get('content', '')
+
+    # Determine type based on contentType
+    if 'PLAYLIST' in content_type:
+        info['type'] = 'playlist'
+        info['playlist_type'] = 'playlist'
+        info['id'] = content_id
+        info['video_count'] = None
+        info['first_video_id'] = None
+
+        # Try to get video count from metadata
+        metadata_rows = lockup_metadata.get('metadata', {})
+        for row in metadata_rows.get('contentMetadataViewModel', {}).get('metadataRows', []):
+            for part in row.get('metadataParts', []):
+                text = part.get('text', {}).get('content', '')
+                if 'video' in text.lower():
+                    info['video_count'] = extract_int(text)
+    elif 'VIDEO' in content_type:
+        info['type'] = 'video'
+        info['id'] = content_id
+        info['view_count'] = None
+        info['approx_view_count'] = None
+        info['time_published'] = None
+        info['duration'] = None
+
+        # Extract duration/other info from metadata rows
+        metadata_rows = lockup_metadata.get('metadata', {})
+        for row in metadata_rows.get('contentMetadataViewModel', {}).get('metadataRows', []):
+            for part in row.get('metadataParts', []):
+                text = part.get('text', {}).get('content', '')
+                if 'view' in text.lower():
+                    info['approx_view_count'] = extract_approx_int(text)
+                elif 'ago' in text.lower():
+                    info['time_published'] = text
+    elif 'CHANNEL' in content_type:
+        info['type'] = 'channel'
+        info['id'] = content_id
+        info['approx_subscriber_count'] = None
+    else:
+        info['type'] = 'unsupported'
+        return info
+
+    # Extract thumbnail from contentImage
+    content_image = item.get('contentImage', {})
+    collection_thumb = content_image.get('collectionThumbnailViewModel', {})
+    primary_thumb = collection_thumb.get('primaryThumbnail', {})
+    thumb_vm = primary_thumb.get('thumbnailViewModel', {})
+    image_sources = thumb_vm.get('image', {}).get('sources', [])
+    if image_sources:
+        info['thumbnail'] = image_sources[0].get('url', '')
+    else:
+        info['thumbnail'] = ''
+
+    # Extract author info if available
+    info['author'] = None
+    info['author_id'] = None
+    info['author_url'] = None
+
+    # Try to get first video ID from inline player data
+    item_playback = item.get('itemPlayback', {})
+    inline_player = item_playback.get('inlinePlayerData', {})
+    on_select = inline_player.get('onSelect', {})
+    innertube_cmd = on_select.get('innertubeCommand', {})
+    watch_endpoint = innertube_cmd.get('watchEndpoint', {})
+    if watch_endpoint.get('videoId'):
+        info['first_video_id'] = watch_endpoint.get('videoId')
+
+    info.update(additional_info)
+    return info
+
+
 def extract_item_info(item, additional_info={}):
     if not item:
         return {'error': 'No item given'}
@@ -243,6 +326,10 @@ def extract_item_info(item, additional_info={}):
         info['type'] = 'unsupported'
         return info
 
+    # Handle new lockupViewModel format (YouTube 2024+)
+    if type == 'lockupViewModel':
+        return extract_lockup_view_model_info(item, additional_info)
+
     # type looks like e.g. 'compactVideoRenderer' or 'gridVideoRenderer'
     # camelCase split, https://stackoverflow.com/a/37697078
     type_parts = [s.lower() for s in re.sub(r'([A-Z][a-z]+)', r' \1', type).split()]
@@ -441,6 +528,9 @@ _item_types = {
     'channelRenderer',
     'compactChannelRenderer',
     'gridChannelRenderer',
+
+    # New viewModel format (YouTube 2024+)
+    'lockupViewModel',
 }
 
 def _traverse_browse_renderer(renderer):