Sessions leave redacted logs; viewers wait for a member relay's source before opening it

Logs: one redaction pass (query strings to names, member tokens,
passwords, cookies, auth headers) for every line; daily files with size
and age caps in the app (hosted server included) and the dedicated
server (--log-dir); swaps, relay channels, per-member /r /m /j outcomes,
server fetches, mpv load errors, yt-dlp runs. Settings > About: Copy
diagnostics, Open logs folder.

Bilibili through someone else: the viewer opened /r/ before the source
dialled in; the server holds that request and mpv gives up after 5 s
("could not be opened"). Viewers now open a member relay once it is
live, the putter starts its source before its own player, and track
sizes are read in parallel.

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

packages/server/lib/src/serve.dart

@@ -12,7 +12,7 @@ import 'sync_server.dart';
 ///
 /// On [events] it reports `{'t':'ready','port':p,'stop':SendPort}` or
 /// `{'t':'error','message':m}`, and forwards log records as
-/// `{'t':'log','level','logger','message'[,'error']}`. Sending
+/// `{'t':'log','level','logger','message'[,'error'][,'stack']}`. Sending
 /// `{'t':'stop'}` to the `stop` port stops the server; the returned future
 /// completes once it is down. `{'t':'file','path':p,'reply':SendPort}` makes
 /// a file on this machine the hosted file (the hosting app's in-session file
@@ -29,6 +29,7 @@ Future<void> serve(Map<String, Object?> config, {SendPort? events}) async {
           'logger': r.loggerName,
           'message': r.message,
           if (r.error != null) 'error': '${r.error}',
+          if (r.stackTrace != null) 'stack': '${r.stackTrace}',
         }));
   }
   final SyncServer server;