Add the Playwright mock e2e for offline pass-and-play (Chromium+WebKit):
create a 2-seat hotseat with a PIN-locked seat, verify the rack is
withheld, unlock (wrong then right PIN), host-skip the current turn, and
terminate from the lobby behind the master PIN.
The e2e surfaced a persistence bug: the roster PINs are $state proxies,
which fail structured-clone on the IndexedDB put (silently — best-effort
store), so a created hotseat game vanished on reload. Snapshot the seats
+ host PIN to plain objects at the create() call site.
Ilia Denisov