feat: add autonomous fiscal completion v1

central/app/product_data_provider.py

@@ -0,0 +1,49 @@
+"""Offline-safe product data provider boundary and permanent cache record."""
+
+from dataclasses import dataclass
+from datetime import datetime, timezone
+import hashlib
+import json
+from typing import Any, Protocol
+
+
+@dataclass(frozen=True)
+class ProviderRecord:
+    provider: str
+    provider_record_version: str
+    gtin: str
+    retrieved_at: str
+    raw_hash: str
+    normalized_data: dict[str, Any]
+    fiscal_authority: str = "OBSERVATION_ONLY"
+    cache_allowed: bool = False
+    redistribution_allowed: bool = False
+
+
+class ProductDataProvider(Protocol):
+    def lookup_gtin(self, gtin: str) -> ProviderRecord | None: ...
+
+
+def normalize_record(provider: str, version: str, gtin: str, data: dict[str, Any]) -> ProviderRecord:
+    normalized = {str(key): value for key, value in sorted(data.items()) if value not in (None, "")}
+    raw_hash = hashlib.sha256(json.dumps(normalized, ensure_ascii=False, sort_keys=True, default=str).encode("utf-8")).hexdigest()
+    return ProviderRecord(provider, version, str(gtin), datetime.now(timezone.utc).isoformat(), raw_hash, normalized)
+
+
+def cache_key(gtin: str, provider: str, provider_record_version: str) -> str:
+    return f"{gtin}:{provider}:{provider_record_version}"
+
+
+def result_cache_key(product: dict[str, Any], candidates: list[str], datasets: dict[str, str], prompt: str, model: str) -> str:
+    payload = {"product": product, "candidates": candidates, "datasets": datasets, "prompt": prompt, "model": model}
+    return hashlib.sha256(json.dumps(payload, ensure_ascii=False, sort_keys=True, default=str).encode("utf-8")).hexdigest()
+
+
+class LocalBulkDatasetProvider:
+    """Offline provider backed by explicitly supplied records; never performs I/O."""
+
+    def __init__(self, records: dict[str, ProviderRecord] | None = None):
+        self.records = records or {}
+
+    def lookup_gtin(self, gtin: str) -> ProviderRecord | None:
+        return self.records.get(str(gtin))