Bring docs in sync with recent features (pending balance, SSE, per-player reveal)

CLAUDE.md: bumped the stale test count (54 -> 76), added "Balance display"
and "Real-time updates (SSE)" sections, and rewrote the DRAW section's
frontend-reveal paragraph to describe the actual current behavior (dual
status/result boxes gated by user_played, closes_at-anchored reveal delay,
localStorage persistence, the last-round-result backstop) instead of the
older single-box design. Refined the "no history endpoints" known gap now
that GET /users/me/last-round-result exists (still not general history).

README.md: same test count fix, expanded coverage list.

docs/: fixed a pre-existing broken link in setup.md (admin-guide.md ->
guida-admin.md), added a note in running-the-server.md that editing the
bind-mounted Caddyfile needs an explicit `docker compose restart caddy`
(discovered while adding the SSE Caddy config in a prior change), and
rewrote guida-utente.md's draw/reveal section plus the balance/withdrawal
sections to match what the UI actually does now. guida-admin.md was
reviewed but needed no changes.

app/static/style.css: dropped `.toast.info`, dead since the toast-based
loss notification it styled was replaced by the persistent result box.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/setup.md

@@ -93,7 +93,7 @@ pip install -e ".[dev]"
 ## 6. Impostare l'indirizzo delle fee
 
 Prima che il primo round possa pagare, un admin deve impostare `fee_address`
-tramite il pannello admin o l'API — vedi [admin-guide.md](admin-guide.md). I
+tramite il pannello admin o l'API — vedi [guida-admin.md](guida-admin.md). I
 payout si rifiutano di partire finché non è impostato.
 
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