Multiplayer: joining a lobby can hang forever, blocking all further join attempts

What happens: a player joins a lobby, the fullscreen loader appears and never goes away. Worse, from that point on every further join attempt is silently ignored for the rest of the session, so the player has to reload the page.

Why: after sending the joinGame message, the client waits for a peerId message with no timeout. The TODO in the code already describes exactly this case:

https://github.com/4ian/GDevelop/blob/1a0661d104ace07d55965d52fb359bddcd485e58/Extensions/Multiplayer/multiplayertools.ts#L1097-L1101

If peerId never arrives, onLobbyQuickJoinFinished is never called, so the loader is never hidden and _isQuickJoiningOrStartingAGame stays true — which makes both quickJoinLobby and quickJoinWithLobbyID return early forever. Every other failure path calls onLobbyQuickJoinFinished; this one has no exit at all.

The game cannot even detect it: IsSearchingForLobbyToJoin returns that same flag, so it stays true and no condition distinguishes "connecting" from "stuck".

Suggested fix: time out the wait for peerId (the ~10s the TODO suggests) and call onLobbyQuickJoinFinished with a new QuickJoinFailureReason such as TIMEOUT, so QuickJoinJustFailed fires and the player can retry.

Workaround, for reference: count the seconds spent with IsSearchingForLobbyToJoin true and past ~8s run

try { gdjs.multiplayerComponents.displayLoader(runtimeScene, false); } catch (e) {}
try { gdjs.multiplayerPeerJsHelper.connect('join-recovery-probe-' + Date.now()); } catch (e) {}

The failed connection raises peer-unavailable and reaches onPeerUnavailable, the only path that clears the flag without reloading the page. It works, but it depends entirely on private internals.

Reproduces intermittently on gd.games. GDevelop version: 5.6.0 (build 277). Line numbers refer to commit 1a0661d.