revert: drop the YouTube cookies/PO-token/proxy workarounds (back to pre-saga state)

None of it got downloads working on the flagged datacenter IP (web_music media
403, then 429 rate-limiting), so revert the whole lot to keep things clean:
- config.js: remove potProviderUrl + ytdlpProxy
- ytdlp.js: remove potArgs/proxyArgs; player_client back to web_music,default
- novasonic-server.js: remove pot/proxy args from importer resolve
- docker-compose.yml: remove the bgutil-provider service + backend env/plugin/depends_on
- CHANGELOG: drop the [2.2] section

Kept the one genuine fix: a failed direct-link download now reports failure
(moved its note into [2.1]).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docker-compose.yml

@@ -33,28 +33,15 @@ services:
       - MAX_PARALLEL=${MAX_PARALLEL:-2}
       - DOWNLOAD_BACKEND=${DOWNLOAD_BACKEND:-ytdlp}
       - TICKETMASTER_API_KEY=${TICKETMASTER_API_KEY}
-      # PO token provider (bgutil) — lets yt-dlp download from datacenter IPs without cookies/account.
-      - POT_PROVIDER_URL=http://bgutil-provider:4416
-    depends_on:
-      - bgutil-provider
     command: >
       sh -c "
         apt-get update && apt-get install -y --no-install-recommends python3 python3-pip ffmpeg curl git && rm -rf /var/lib/apt/lists/* &&
         curl -sL https://github.com/yt-dlp/yt-dlp/releases/latest/download/yt-dlp -o /usr/local/bin/yt-dlp && chmod a+rx /usr/local/bin/yt-dlp &&
-        pip install --break-system-packages spotapi 'git+https://github.com/TzurSoffer/spotify-downloader' bgutil-ytdlp-pot-provider &&
+        pip install --break-system-packages spotapi 'git+https://github.com/TzurSoffer/spotify-downloader' &&
         mkdir -p /deps && cd /deps && npm install express kuromoji &&
         cd /app && NODE_PATH=/deps/node_modules node novasonic-server.js
       "
 
-  # ── PO token provider (bgutil) — mints YouTube "Proof of Origin" tokens so yt-dlp can download
-  #    from a datacenter IP without cookies or an account. Paired with the bgutil-ytdlp-pot-provider
-  #    plugin installed in the backend above. Port 4416 is internal only (no reverse proxy needed). ──
-  bgutil-provider:
-    image: brainicism/bgutil-ytdlp-pot-provider:latest
-    container_name: bgutil-provider
-    restart: unless-stopped
-    init: true
-
   # ── Scrobble service (isolated timestamped play-log → stats + Wrapped) ────────
   novasonic-scrobble:
     image: node:22-slim