Release 5.5.0

Also stops one benign libmpv message being logged as an error: `after
creating texture: OpenGL error INVALID_ENUM` comes from the GL driver, arrives
several times per playback start and per fullscreen toggle, and playback
continues regardless. Hundreds of lines a session buried the errors that
matter -- it is a debug line now.

Verified end to end on the real display with an actual video playing: ten tab
switches and four fullscreen toggles while frames were rendering, position
advancing throughout, the render context intact, no crash, and an empty error
log afterwards.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -8,7 +8,7 @@ Kept as the work happens, not assembled at release time. Format is
 with its history. SageTube's own versions start below and are the ones this file
 records.
 
-## Unreleased
+## 5.5.0 — 2026-08-09
 
 ### Added
 
@@ -88,6 +88,10 @@ records.
 
 ### Fixed
 
+- The error log filled with hundreds of `after creating texture: OpenGL error
+  INVALID_ENUM` lines per session. They come from the GL driver, playback
+  continues regardless, and they buried the errors that do matter, so they are
+  logged at debug level now.
 - The player's cookie and proxy options were joined with commas and never
   escaped, so a cookie path or a proxy URL containing one silently truncated
   the option and produced a bogus one. The geo-bypass proxy was honoured by the