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>

CHANGELOG.md

@@ -64,28 +64,6 @@ Versioning: two-part `MAJOR.MINOR` — each release bumps the minor (features an
 
 ---
 
-## [2.2] — 2026-08-14
-
-Keeps downloads working after YouTube began blocking datacenter IPs, and fixes a related
-false-success in the UI.
-
-### Added
-- **PO token provider (bgutil)** — YouTube now 403s media downloads from datacenter IPs without a
-  **PO ("Proof of Origin") token** that yt-dlp can't compute itself (seen first as "Sign in to
-  confirm you're not a bot", then `HTTP 403` on the audio stream). A self-hosted **`bgutil-provider`**
-  container (`brainicism/bgutil-ytdlp-pot-provider`) mints the tokens and the matching
-  `bgutil-ytdlp-pot-provider` plugin (installed in the backend) hands them to yt-dlp — **no cookies or
-  account required**. Wired into the download cascade, the YTM search probe and the importer resolve,
-  guarded by `POT_PROVIDER_URL` (empty → yt-dlp runs exactly as before). Deploy: `docker compose up -d`.
-
-### Fixed
-- **A failed direct-link download reported success** — the direct-URL path returned `success` even
-  when no audio was produced (e.g. the YouTube 403), so the job showed "Fertig!" and the UI (web +
-  Android) said the track was added. It now reports failure with a clear message ("Download
-  fehlgeschlagen — YouTube hat den Abruf blockiert (403)").
-
----
-
 ## [2.1] — 2026-08-14
 
 Builds on the 2.0 listening archive with a **head-to-head "Musik-Match"**, brings the **artist pin**
@@ -110,6 +88,9 @@ to Android at parity with web, and fixes a batch of same-name-artist and player
   as avatar chips, matching the Android app (previously plain text).
 
 ### Fixed
+- **A failed direct-link download reported success** — the direct-URL path returned `success` even
+  when no audio was produced (e.g. a YouTube 403), so the job showed "Fertig!" and the UI (web +
+  Android) said the track was added. It now reports failure with a clear message.
 - **Artist pin — search & similar artists (Web + Android)** — a pinned artist now shows the correct
   Deezer photo in library search (not the wrong same-name person's), and its "Similar Artists" use
   Deezer's **related** for the pinned artist instead of Last.fm's list (which was keyed to the