feat(5.6): observabilitate + jurnal aplicatie + lifecycle trimiteri blocate

Implementeaza PRD 5.6 complet (14 stories, TDD). Doua axe:

Lifecycle trimiteri blocate (Val A):
- submissions_admin.py: sterge/repune scoped (404 cross-account inaintea lui 409 stare)
- reactivare dedup peste `error` cu CAS (WHERE id=? AND status='error'), creds noi in
  submissions + accounts.rar_creds_enc; worker invalideaza sesiunea RAR la creds proaspete
  (JWT 30h vechi nu mai trimite cu parola gresita); camp aditiv `reactivated:true`
- retentie randuri blocate 30z; purge_expired exclude queued/sending; purge_after curatat
  la reactivare/requeue
- API DELETE /v1/prezentari/{id} + /repune (200+JSON); UI butoane + bulk + banner actionabil

Observabilitate:
- app/observ.py log_event: dublu canal app_events (DB) + RotatingFileHandler per-proces,
  redactare creds/PII la scriere (redact_pii/vin_partial)
- request_id middleware + X-Request-ID pe toate raspunsurile
- handler global excepții -> 500 envelope 6-chei + request_id (traceback doar in jurnal)
- audit cerere API (api_prezentari/api_auth_esuat) + audit worker (rar_login/tranzitii)
- tab "Jurnal" filtrabil scoped (non-admin doar contul sau); retentie jurnal 90z
- rar_error expus in GET /v1/prezentari/{id} (recovery observabil)

pytest -q: 741 passed, 0 failed. Docs: PRD raport VERIFY, contract endpointuri noi, ROADMAP.

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

app/errors.py

@@ -162,6 +162,14 @@ CATALOG: dict[str, dict[str, str]] = {
             " (ghilimele duble, acolade inchise corect)."
         ),
     },
+    "EROARE_INTERNA": {
+        "problema": "Eroare interna a gateway-ului",
+        "fix": (
+            "Nu e o problema de date trimise de tine. Reincearca peste cateva"
+            " momente; daca persista, contacteaza administratorul cu identificatorul"
+            " cererii (request_id) afisat."
+        ),
+    },
 }