Resolve an address to its unambiguous historic EPC UPRN 🟩

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

repositories/historic_epc/historic_epc_resolver.py

@@ -38,4 +38,11 @@ class HistoricEpcResolver:
     ) -> Optional[tuple[str, str, float]]:
         """``(uprn, matched_address, lexiscore)`` for an unambiguous rank-1
         match, else None (no data / ambiguous tie / zero score)."""
-        raise NotImplementedError
+        matches = self.match(user_address, postcode)
+        uprn = matches.unambiguous_uprn()
+        if not uprn or uprn == "nan":
+            return None
+        top = matches.top()
+        if top is None:
+            return None
+        return uprn, top.record.address, top.lexiscore