feat(5.15+5.14): CLOSE — fix-uri code-review + embeddings functional

5.15 (propagare design + dashboard editare) si 5.14 (mapare LLM distilata)
inchise dupa /code-review high. 8 buguri reparate TDD:

- HIGH modal nu se deschidea pe randul slim (base.html: trimitere-slim)
- HIGH /repune trunchia prestatii (declaratie incompleta la RAR) -> iterare
  peste existing, codes pozitional
- HIGH embeddings incarca model ~230MB degeaba pe corpus gol -> poarta has_corpus()
- HIGH picker chips gol pe re-render eroare -> conn/account_id pe toate ramurile
- MED obs re-derivat dupa stergere explicita -> _merge_override pastreaza obs=''
- MED mapare salvata fara denumire poluă GOLD -> _record_gold_validation guard
- MED typo nome_prestatie -> nume_prestatie in select /repune
- MED bucketare timp +3h gresita iarna -> SQLite localtime + TZ=Europe/Bucharest

Embeddings WIRE-uit functional (PRD #15, decizie user): ensure_embeddings_corpus
construieste corpus din nomenclator, gated pe AUTOPASS_EMBEDDINGS_ENABLED (default
off). Marime model corectata ~50MB->~230MB (estimare PRD gresita).

Cleanup: hoist load_* din bucla bulk-fix; import re la top.
Regresie: 1256 passed, 1 deselected (live), 0 failed.

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

app/payload_view.py

@@ -125,6 +125,10 @@ def prezentare_din_payload(payload: str | dict | None) -> dict[str, str]:
     # altfel ar expune denumirea RAR drept op. de service, ceea ce e semantic incorect.
     op_service_denumire = _clean_str(item.get("denumire")) if op_service_cod else ""
 
+    # obs: text liber observatii (camp RAR, optional). Conventie goala "" (nu EMPTY).
+    # US-005 PRD 5.15: obs traieste in payload_json (nu coloana separata).
+    obs = _clean_str(data.get("obs"))
+
     return {
         "vehicul_nr": nr or EMPTY,
         "vin": vin or EMPTY,
@@ -137,4 +141,5 @@ def prezentare_din_payload(payload: str | dict | None) -> dict[str, str]:
         # Chei cu conventie goala "" (nu EMPTY) — vezi comentariu de mai sus
         "op_service_cod": op_service_cod,
         "op_service_denumire": op_service_denumire,
+        "obs": obs,
     }