Add regression test for non-completed status with valid content

Pin the content-first parsing behavior: status='incomplete' with usable
output should return content, not exit. Addresses P2 from gpt-5.4-pro review.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: igerber

tests/test_openai_review.py

@@ -1710,6 +1710,20 @@ def test_status_none_with_valid_output_succeeds(self, review_mod, mock_urlopen):
         content, _ = review_mod.call_openai("test", "gpt-5.4", "fake-key")
         assert content == "Good review."
 
+    def test_incomplete_status_with_valid_content_succeeds(self, review_mod, mock_urlopen):
+        """Non-completed status should still return content when output is usable."""
+        mock_urlopen["response_data"] = {
+            "status": "incomplete",
+            "output_text": None,
+            "output": [{
+                "type": "message",
+                "content": [{"type": "output_text", "text": "Partial but usable."}],
+            }],
+            "usage": {"input_tokens": 10, "output_tokens": 5},
+        }
+        content, _ = review_mod.call_openai("test", "gpt-5.4", "fake-key")
+        assert content == "Partial but usable."
+
     def test_output_text_convenience_field_used(self, review_mod, mock_urlopen):
         """When output_text is populated (SDK-style), use it directly."""
         mock_urlopen["response_data"] = {