- Add a request timeout (AbortController) to the frontend's call() helper, so a
hung server request no longer freezes the entire polling chain silently.
- Add GET /users/me/last-round-result: a durable, DB-backed fallback for the
round outcome, since /rounds/current drops winner_user_id the instant a
round flips from "paying_out" to "closed" — a backgrounded tab or a missed
poll could otherwise mean a player never learns whether they won.
- Refresh the balance display when a win is revealed (live or via the new
backstop), instead of leaving the pre-payout balance on screen.
- Guard refreshRound() with a session-epoch counter so an in-flight request
from a previous login can't re-arm the poll loop after logout, which
previously produced a duplicate "zombie" polling chain.
davide
f822911128