fix(offline): delete a finished local game from the device, not the network

The lobby's finished-game delete (hide) always called gateway.hideGame; for a
local (offline) game the transport kill switch refused it, so it toasted and the
game stayed. Route by id: a local game is removed from the device store + the
source cache (LocalSource.delete), an online game still hides on the backend.

ui/src/lib/gamesource.ts

@@ -40,6 +40,7 @@ export const localSource = {
   draftSave: (_id, _json) => load().then((s) => s.draftSave()),
   create: (opts) => load().then((s) => s.create(opts)),
   list: () => load().then((s) => s.list()),
+  delete: (id) => load().then((s) => s.delete(id)),
   // events must return the unsubscribe synchronously (the screen subscribes in onMount), so it wires
   // the real subscription once the engine loads and, until then, cancels a pending subscribe.
   events: (id, onEvent) => {
@@ -53,7 +54,7 @@ export const localSource = {
       unsub();
     };
   },
-} satisfies GameLoopSource & Pick<LocalSource, 'events' | 'create' | 'list'>;
+} satisfies GameLoopSource & Pick<LocalSource, 'events' | 'create' | 'list' | 'delete'>;
 
 /**
  * gameSource returns the source that runs the game with the given id: the local engine for a local