bomberman: sunete (sfx), raza initiala 1, powerup-uri raza/bombe

Feedback user: nu se aud sunete, raza prea mare, lipsesc powerup-urile.

- sfx(type) WebAudio local in arcade: bomb/explosion/enemy/powerup/death;
  beep(ok) din libJS ramane pentru raspuns corect/gresit.
- raza fixa EXPLOSION_RANGE=3 -> bombRange variabil de la BASE_RANGE=1
  (Bomberman clasic); maxBombs de la BASE_BOMBS=1.
- powerup-uri: la spargerea cutiei, sansa 0.32 sa cada flacara (raza+1)
  sau bomba (bombe+1); ridicate mergand pe ele; HUD arata bombe/raza.
- fix: powerup-ul cadea pe celula cutiei si checkExplosionHits il stergea
  instant -> colectez brokenBoxes, drop dupa checkExplosionHits.

Hooks __game: powerups/bombRange/maxBombs/dropPowerupAt. Smoke 27/27.

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

AGENTS.md

@@ -20,8 +20,8 @@ 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: 26/26
-npx playwright test tests/smoke.mjs --grep @regresie   # regresie: 14
+npx playwright test tests/smoke.mjs                    # suita completă: 27/27
+npx playwright test tests/smoke.mjs --grep @regresie   # regresie: 15
 npx playwright test tests/smoke.mjs --grep @campanie   # campanie E2E: 12
 ```