fix(offline): give the local human seat the real account id

In a local game the human seat's account id was a synthetic 'local:human:0',
so seatName's `accountId === session.userId` check never matched: the game
header rendered BOTH seats as 🤖 (the vs_ai fallback), and the lobby's
groupGames could not find the viewer's seat, so a human's turn read as
'Their turn' with the hourglass. Carry the real account id on the human seat
(create -> record -> GameView); the robot keeps its synthetic id.

Local games created before this fix keep the old display (no migration).

ui/src/screens/NewGame.svelte

@@ -74,7 +74,9 @@
           seed: randomSeed(),
           multipleWords: multipleWordsForRequest(v, multipleWords),
           seats: [
-            { kind: 'human', name: app.profile?.displayName ?? 'You' },
+            // The human seat carries the real account id so the game screen and the lobby identify
+            // "you" and the correct turn exactly as for an online game (the robot uses a synthetic id).
+            { kind: 'human', name: app.profile?.displayName ?? 'You', accountId: app.session?.userId },
             { kind: 'robot', name: 'Robot' },
           ],
         });