feat(api): endpoint dry-run POST /v1/prezentari/valideaza (PRD 5.2)

Valideaza payload + mapare si intoarce verdictul real (status_estimat
queued/needs_data/needs_mapping + erori [{field,message}] + coduri nemapate
+ prestatii rezolvate) FARA enqueue, fara creds, zero scriere DB. "Magical
moment" pentru integratori (ROAAUTO / soft propriu / punte VFP).

Cheia de design: helper pur partajat classify_prezentare (mapping.py) folosit
de AMBELE rute, ca dry-run-ul sa nu poata diverge de trimiterea reala
(invariant de corectitudine). create_prezentari refactorizat pe el cu
comportament identic (test_api.py verde).

Scope minim (decizie user): doar validare+mapare, fara idempotency/duplicat
(idempotency.py neatins); descoperibilitate in hub /integrare amanata.

VERIFY context curat PASS (577 teste; E2E API cu cele 3 verdicte + COUNT(*)=0
dupa dry-run). /code-review high: 0 findings.

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

app/mapping.py

@@ -217,6 +217,61 @@ def load_mapping_meta(conn, account_id: int | None) -> dict[str, dict]:
     }
 
 
+def classify_prezentare(
+    content: dict,
+    mapping: dict[str, str],
+    mapping_meta: dict[str, dict],
+) -> dict:
+    """Helper pur de clasificare: reproduce EXACT logica create_prezentari fara DB/efecte.
+
+    Apelat de AMBELE rute (POST /v1/prezentari si POST /v1/prezentari/valideaza) pentru
+    a garanta acelasi verdict — invariantul de corectitudine dry-run (PRD 5.2).
+
+    Intoarce {"status", "rar_error", "resolved", "unmapped", "errors", "content"}.
+    "content" = copia actualizata (VIN/nr canonicalizat + prestatii rezolvate).
+    """
+    from .idempotency import canonicalize_row  # import local: evita circular (mapping <- idempotency)
+
+    c = dict(content)
+    canon = canonicalize_row(c)
+    c.update({
+        "vin": canon["vin"],
+        "nr_inmatriculare": canon["nr_inmatriculare"],
+        "odometru_final": canon["odometru_final"],
+    })
+
+    resolved, unmapped = resolve_prestatii(c.get("prestatii"), mapping)
+    c["prestatii"] = resolved
+
+    if unmapped:
+        status = "needs_mapping"
+        rar_error = json.dumps({"unmapped": unmapped}, ensure_ascii=False)
+        errors: list[dict] = []
+    else:
+        errors = validate_prezentare(c)
+        if errors:
+            status = "needs_data"
+            rar_error = json.dumps(errors, ensure_ascii=False)
+        elif has_no_auto_send(resolved, mapping_meta):
+            status = "needs_mapping"
+            rar_error = json.dumps(
+                {"auto_send": "cod mapat cu auto_send=0; review manual inainte de trimitere"},
+                ensure_ascii=False,
+            )
+        else:
+            status = "queued"
+            rar_error = None
+
+    return {
+        "status": status,
+        "rar_error": rar_error,
+        "resolved": resolved,
+        "unmapped": unmapped,
+        "errors": errors,
+        "content": c,
+    }
+
+
 def has_no_auto_send(resolved: list[dict], mapping_meta: dict[str, dict]) -> bool:
     """Verifica daca vreun item rezolvat via mapping are auto_send=0.