Raise truncation error when PasHub stops serving pages before the full evidence set arrives 🟩

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

infrastructure/pashub_fetcher/pashub_client.py

@@ -203,6 +203,12 @@ class PashubClient:
 
             if len(results) >= total:
                 break
+            if not batch:
+                raise TruncatedEvidenceListError(
+                    f"PasHub returned {len(results)} of {total} evidence files for "
+                    f"job {job_id} - it stopped serving pages before the full "
+                    f"evidence set arrived, so the evidence set is incomplete."
+                )
             page_index += 1
 
         return [EvidenceFileData.from_api(item) for item in results]