Timer Calm (T10 / §Design pct.10): ceas campanie opt-in

Ceas M:SS in bara chrome a campaniei. Opt-in din builder (camp "Timp limita
(minute)", default 0 = fara; cleanState coerce 0..120).

- porneste exact la "Incepe aventura" (intro necronometrat)
- deadline ABSOLUT in sessionStorage -> resume nu reseteaza ceasul
- sub 1 min -> auriu (.low); expirare -> ingheata 0:00 + marcaj discret
  (.expired), jocul curge nestingherit (zero penalizare, stelele raman)
- fara rosu pulsant (public copii) -> reduced-motion safe by default
- exemplu-campanie.html regenerat (ramane fara timer - opt-in, ca vocea)

Fundatie pentru muzica T10 (accelerare sub 1 min) + footer diploma.
Test nou (smoke 29/29): format M:SS, prag auriu, freeze la expirare,
jocul continua dupa expirare, resume pastreaza ceasul.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

AGENTS.md

@@ -20,9 +20,9 @@ sursa de adevăr tehnică pentru agenți.
 python3 -m http.server 8000
 
 # Teste (Playwright; fără package.json commitat — vezi tests/AGENTS.md):
-npx playwright test tests/smoke.mjs                    # suita completă: 28/28
+npx playwright test tests/smoke.mjs                    # suita completă: 29/29
 npx playwright test tests/smoke.mjs --grep @regresie   # regresie: 16
-npx playwright test tests/smoke.mjs --grep @campanie   # campanie E2E: 14
+npx playwright test tests/smoke.mjs --grep @campanie   # campanie E2E: 15
 ```
 
 ## Durable Rules (repo-wide)