Keep partial rewrite results from LLM batches

tests/test_stage4_rewrite.py

@@ -107,6 +107,27 @@ class Stage4RewriteTests(unittest.TestCase):
         self.assertEqual([item.title for item in rewritten], ["OpenAI launches GPT-5 API", "OpenAI launches GPT-5 API"])
         self.assertEqual(report["fallback_count"], 2)
 
+    def test_rewrite_items_keeps_partial_batch_rewrites_when_some_ids_are_missing(self):
+        items = [news_item("a"), news_item("b"), news_item("c")]
+
+        def llm_call(prompt):
+            return json.dumps(
+                {
+                    "rewrites": [
+                        {"id": "a", "title": "title a", "summary": "summary a", "flags": []},
+                        {"id": "c", "title": "title c", "summary": "summary c", "flags": []},
+                    ]
+                }
+            )
+
+        rewritten, report = rewrite_items(items, llm_call=llm_call, batch_size=3, max_fallback_ratio=0.5)
+
+        self.assertEqual([item.title for item in rewritten], ["title a", "OpenAI launches GPT-5 API", "title c"])
+        self.assertEqual(report["rewritten_count"], 2)
+        self.assertEqual(report["fallback_count"], 1)
+        self.assertEqual(report["missing_rewrite_count"], 1)
+        self.assertEqual(report["blocking_errors"], [])
+
     def test_rewrite_items_defaults_to_large_batches_to_reduce_llm_requests(self):
         items = [news_item(str(index)) for index in range(61)]
         batch_sizes = []