feat(T5): editor web mapare operatii (hibrid + fuzzy + on-demand needs_mapping)

T5 reinterpretat: nu import DBF, ci editor web al maparii operatie ROAAUTO ->
cod RAR, cu fuzzy lookup si validare de catre utilizator.

- Contract hibrid: item prestatie accepta cod_prestatie (RAR direct, back-compat)
  SAU cod_op_service+denumire (mapat de gateway prin operations_mapping).
- Ingestie: op intern necunoscut -> submission needs_mapping (nu pleaca la RAR);
  codul rezolvat se scrie inapoi in payload_json -> payload builder + worker neatinse.
- Editor HTMX (_mapari.html + GET /_fragments/mapari, POST /mapari): listeaza
  op-urile nemapate, fuzzy preselecteaza codul RAR, save -> re-rezolvare automata
  (queued / needs_data).
- Fuzzy: rapidfuzz.token_sort_ratio pe denumire normalizata (fara diacritice).
- Nomenclator: seed fallback 18 coduri la boot (offline) + refresh live din worker.
- Cont default id=1 cat timp auth API-key (CORE) nu exista (account_id NULL).
- Endpointuri API: GET /v1/mapari/pending, POST /v1/mapari (respinge cod inexistent).
- 15 teste noi (tests/test_mapping.py); 69 pass total.
- Contract actualizat (docs/api-rar-contract.md), rapidfuzz==3.14.5 in requirements.

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

app/db.py

@@ -32,6 +32,11 @@ def init_db() -> None:
     try:
         conn.executescript(_SCHEMA.read_text(encoding="utf-8"))
         _migrate(conn)
+        # Seed fallback nomenclator (doar daca e gol) ca editorul de mapari + fuzzy
+        # sa mearga inainte ca worker-ul sa fi luat lista live din RAR.
+        from .mapping import seed_nomenclator_if_empty
+
+        seed_nomenclator_if_empty(conn)
     finally:
         conn.close()