feat(5.19): auto-send toggle per cont + tinere manuala randuri (held)

Comutator accounts.auto_send_enabled per cont: Auto OFF (default) tine randurile
la ingestie (submissions.held=1), worker-ul (claim_one AND held=0) le sare pana la
eliberare umana (per rand/bulk/auto-release OFF->ON). Snapshot held prin chokepoint
unic held_for_account pe toate caile de ingestie (API, import, reresolve, reactivare).

- schema/migrare: coloana held + index partial idx_submissions_held; auto_send_enabled
- API: echo onest held+motiv (US-010), ruta /prezentari/{id}/trimite-acum
- web: toggle header, modal confirmare tipata, buton Trimite per rand + Trimite toate,
  banner coada tinuta imbatranita (L.142), contor "In asteptare (manual)"
- worker: expire_held (US-008, inchide gaura retentie PII), metrics held gauges
- ops: tools/carantina_held + runbook rollback (R4)

Nota review (/code-review high): re-snapshot held lipseste pe caile repune/corectie
(requeue_submission, post_corectie, bulk-fix) — de aliniat separat cu create_prezentari.

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

app/mapping.py

@@ -23,6 +23,7 @@ from typing import Any
 from rapidfuzz import fuzz, process
 
 from . import errors as err_mod
+from .accounts import held_for_account
 from .nomenclator_seed import FALLBACK_NOMENCLATOR
 from .validation import validate_prezentare
 
@@ -891,10 +892,14 @@ def reresolve_account(conn, account_id: int | None, batch_id: int | None = None)
             )
             stats["needs_data"] += 1
         else:
+            # PRD 5.19 US-002: re-snapshot `held` din comutatorul contului la trecerea
+            # needs_mapping -> queued (chokepoint held_for_account, `acct` deja normalizat
+            # prin account_or_default la intrarea in reresolve_account). Altfel un rand
+            # deblocat din needs_mapping ar pleca automat desi contul e Auto OFF (R2).
             conn.execute(
                 "UPDATE submissions SET status='queued', payload_json=?, rar_error=NULL, "
-                "retry_count=0, next_attempt_at=NULL, updated_at=datetime('now') WHERE id=?",
-                (payload_json, r["id"]),
+                "retry_count=0, next_attempt_at=NULL, held=?, updated_at=datetime('now') WHERE id=?",
+                (payload_json, held_for_account(conn, acct), r["id"]),
             )
             stats["requeued"] += 1
     return stats