fix: skip artist channel results, live notification list update

- Add --match-filter 'webpage_url !*= /browse/' to baseArgs so yt-dlp
  skips YTM artist channel pages returned as search results (previously
  caused recursive channel-upload fetches that wasted time)
- Call _renderNotifList() in _addNotif so playlist-created notifications
  appear immediately without needing a page reload

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/novasonic-server.js

@@ -255,6 +255,9 @@ async function downloadTrack({ jobId, artist, albumArtist, title, album, year, t
     '--no-playlist',
     '--no-warnings',
     '--newline',
+    // Skip artist channel pages that YTM sometimes returns as search result 1;
+    // without this yt-dlp recursively fetches the entire channel uploads playlist.
+    '--match-filter', 'webpage_url !*= /browse/',
   ];
   // Filtered searches: top 5 (fast) and top 10 (wider net when top 5 misses).
   // Unfiltered fallback only needs item 1 (no filter to skip past).