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>

agent/src/gti_fiscal_agent/enrichment.py

@@ -21,7 +21,10 @@ from datetime import datetime, timezone
 logger = logging.getLogger("gti_fiscal_agent.enrichment")
 
 CAPABILITY = "PRODUCT_ENRICHMENT_WRITE_V1"
-ALLOWED_FIELDS = ("CLASSIFICACAO_FISCAL", "CEST", "IPI")            # explicit allowlist; anything else raises before touching SQL
+ALLOWED_FIELDS = ("CLASSIFICACAO_FISCAL", "CEST", "IPI")
+# TECHNICAL_PLACEHOLDER: the SGV refuses a product without NCM, so operators type a filler. It means "not classified yet" (not a human decision) and may be replaced.
+# Explicit per-field allowlist, identical to central/app/enrichment/placeholders.py (parity test). Nothing else is ever overwritten.
+PLACEHOLDERS = {"CLASSIFICACAO_FISCAL": frozenset({"00000000"})}            # explicit allowlist; anything else raises before touching SQL
 READ_FIELDS = ("CODIGO", "PRODUTO", "GTIN", "CODBARRA") + ALLOWED_FIELDS      # the SGV operator types the EAN in CODBARRA; GTIN (fiscal) is mostly empty
 POLL_SECONDS = 2.0
 SAFETY_DIFF_SECONDS = 60.0
@@ -108,6 +111,16 @@ def is_human_overridden(store_path, code, field) -> bool:
 
 
 # ---- Firebird access (injected: `read_conn()` returns a READ-ONLY connection, `write_conn()` a write-capable one, only ever opened by ENABLED mode) ----------------------------------------
+def is_placeholder(field, value) -> bool:
+    text = _text(value)
+    text = "".join(ch for ch in text if ch.isdigit()) if field == "CLASSIFICACAO_FISCAL" else text
+    return text in PLACEHOLDERS.get(field, frozenset())
+
+
+def writable_now(field, value) -> bool:
+    return not _text(value) or is_placeholder(field, value)
+
+
 def _digits(value) -> str:
     return "".join(ch for ch in _text(value) if ch.isdigit())
 
@@ -174,10 +187,14 @@ def write_field(conn, code: str, field: str, value) -> dict:
         if len(rows) != 1:
             conn.rollback()
             return {"outcome": "ABORTED", "reason": "PRODUCT_ROW_NOT_UNIQUE" if rows else "PRODUCT_NOT_FOUND"}
-        if _text(rows[0][0]):
+        raw = rows[0][0]
+        if not writable_now(field, raw):
             conn.rollback()
             return {"outcome": "ABORTED", "reason": "VALUE_ALREADY_SET_NEVER_OVERWRITTEN"}
-        cur.execute(f"UPDATE C000025 SET {field} = ? WHERE CODIGO = ? AND ({field} IS NULL OR TRIM({field}) = '')", (value, code))
+        if _text(raw):                                               # technical placeholder: compare-and-swap on the exact value just read
+            cur.execute(f"UPDATE C000025 SET {field} = ? WHERE CODIGO = ? AND TRIM({field}) = ?", (value, code, _text(raw)))
+        else:
+            cur.execute(f"UPDATE C000025 SET {field} = ? WHERE CODIGO = ? AND ({field} IS NULL OR TRIM({field}) = '')", (value, code))
         if cur.rowcount != 1:
             conn.rollback()
             return {"outcome": "ABORTED", "reason": "UPDATE_ROWCOUNT_NOT_ONE"}
@@ -189,7 +206,7 @@ def write_field(conn, code: str, field: str, value) -> dict:
         same = (float(after) == value) if field == "IPI" and after is not None else _text(after) == value
         if not same:
             return {"outcome": "FAILED", "reason": "POST_WRITE_VERIFICATION_FAILED"}
-        return {"outcome": "APPLIED", "value": value, "rowcount": 1}
+        return {"outcome": "APPLIED", "value": value, "rowcount": 1, "replaced_placeholder": _text(raw) if _text(raw) else None}
     except Exception as error:  # noqa: BLE001
         try:
             conn.rollback()
@@ -345,7 +362,8 @@ class EnrichmentWorker:
         for field in ALLOWED_FIELDS:
             decision = fields.get(field) or {}
             status, value = decision.get("status"), decision.get("value")
-            base = {"field": field, "rule": decision.get("rule"), "kb_status": decision.get("kb_status"), "evidence": decision.get("evidence") or [], "old": None, "new": value}
+            placeholder = _text(current.get(field)) if is_placeholder(field, current.get(field)) else None
+            base = {"field": field, "rule": decision.get("rule"), "kb_status": decision.get("kb_status"), "evidence": decision.get("evidence") or [], "old": placeholder, "new": value}
             if status == "HUMAN_OVERRIDDEN" or overridden.get(field):
                 reports.append({**base, "outcome": "HUMAN_OVERRIDDEN", "reason": "HUMAN_OVERRIDDEN", "new": None})
                 continue