feat: TECHNICAL_PLACEHOLDER (NCM 00000000) is replaceable by the product enrichment; real values preserved; Agent 1.3.4

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

central/app/enrichment/api.py

@@ -10,6 +10,7 @@ from sqlalchemy import select
 from ..blocked_products import upsert_blocker
 from ..config import settings
 from ..models import Installation, ProductEnrichment, ProductFieldAudit
+from .placeholders import is_placeholder
 from .providers import build_providers
 from .quota import ProviderGateway
 from .resolver import FIELDS, resolve
@@ -74,6 +75,9 @@ def router(principal, providers_factory=None):
                 if field in result["fields"]:
                     result["fields"][field] = {"status": "HUMAN_OVERRIDDEN", "value": None, "rule": None, "kb_status": None, "evidence": [], "reason": "valor alterado por uma pessoa; nunca mais preenchido automaticamente"}
             pending = result["state"] in PENDING_STATES
+            for name, decision in result["fields"].items():                    # explain in the audit trail that a technical placeholder was treated as "not classified yet"
+                if is_placeholder(name, current.get(name)):
+                    decision["technical_placeholder"] = str(current.get(name))
             row.gtin, row.description, row.latency_ms = result.get("gtin"), description, latency
             row.attempts = (row.attempts or 0) + 1
             row.status = "PENDING" if pending else "RESOLVED"