Errors: refuse links the probe can't play (with Put it up anyway), plain error texts, and others see who can't play

report.error / state.members[].error (optional, no protocol bump): an
errored member is out of the ready gate until its player opens the media
or the media changes; others see "Bob can't play this: ..." and a mark
on the avatar; your own pill offers Retry (reload).

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

packages/server/lib/src/server_hub.dart

@@ -428,7 +428,7 @@ void mountSyncRoute(
               final report = ReportMessage.fromJson(decoded);
               hub.engine.applyReport(
                   token, report.position, report.buffered, report.eventId,
-                  duration: report.duration, mediaId: report.mediaId, jf: report.jf);
+                  duration: report.duration, mediaId: report.mediaId, jf: report.jf, error: report.error);
               hub.changed();
             case 'ping':
               final ping = PingMessage.fromJson(decoded);