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/models.py

@@ -96,6 +96,10 @@ class SubmissionResult(BaseModel):
     status: str
     id_prezentare: int | None = None
     deduped: bool = False  # True daca idempotency a intors un submission existent
+    # US-012 (decizie /autoplan #19): camp ADITIV. True cand un rand `error` cu aceeasi
+    # cheie de continut a fost RE-ACTIVAT (re-clasificat + creds actualizate) la resubmit.
+    # `deduped` pastreaza semantica actuala (clientii vechi care testeaza `deduped` nu se sparg).
+    reactivated: bool = False
 
 
 class PrezentariResponse(BaseModel):