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/lib/localgame/source.list.test.ts

@@ -51,6 +51,20 @@ describe('LocalSource.list', () => {
     expect(list.every((g) => g.vsAi && g.status === 'active')).toBe(true);
   });
 
+  it('carries the human seat account id into the GameView so the client identifies "you"', async () => {
+    const src = new LocalSource();
+    await src.create({
+      ...opts('local:me', 3n),
+      seats: [
+        { kind: 'human', name: 'You', accountId: 'acct-42' },
+        { kind: 'robot', name: 'Robot' },
+      ],
+    });
+    const [g] = await src.list();
+    expect(g.seats[0].accountId).toBe('acct-42'); // the human's real id, matched against the session
+    expect(g.seats[1].accountId).not.toBe('acct-42'); // the robot keeps a synthetic id
+  });
+
   it('reconstructs a game persisted by a previous session (not in the source cache)', async () => {
     // Seed the store via one source, then list from a fresh source whose in-memory cache is empty.
     await new LocalSource().create(opts('local:old', 7n));