Player: mpv logs at warn (v only while probing the render mode), 4xx fails at once, load errors show

The session player asked libmpv for every v-level message all session and
media_kit drains them on the UI thread: a retry storm could freeze the
window. ffmpeg reconnects only on 5xx, bounded. A load that fails before
a duration is known reports once ('can't play this: HTTP error 403 ...').

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/desktop/pubspec.lock

@@ -138,7 +138,7 @@ packages:
     source: hosted
     version: "1.3.3"
   ffi:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: ffi
       sha256: "6d7fd89431262d8f3125e81b50d3847a091d846eafcd4fdb88dd06f36d705a45"