refactor: unify asset completion workflows

backend/tests/test_stories.py

@@ -593,6 +593,51 @@ class TestAssetRetry:
         assert data["pages"][1]["image_url"] == "https://example.com/retried-page.png"
         mock_image.assert_awaited_once()
 
+    def test_retry_audio_success(
+        self,
+        auth_client: TestClient,
+        test_story,
+        mock_tts_provider,
+    ):
+        response = auth_client.post(
+            f"/api/stories/{test_story.id}/assets/retry",
+            json={"assets": ["audio"]},
+        )
+
+        assert response.status_code == 200
+        data = response.json()
+        assert data["generation_status"] == "completed"
+        assert data["image_status"] == "not_requested"
+        assert data["audio_status"] == "ready"
+        assert data["last_error"] is None
+        mock_tts_provider.assert_awaited_once()
+
+        cached_audio_path = Path(settings.story_audio_cache_dir) / f"story-{test_story.id}.mp3"
+        assert cached_audio_path.is_file()
+
+    def test_retry_audio_failure_updates_status_without_blocking_response(
+        self,
+        auth_client: TestClient,
+        test_story,
+    ):
+        with patch(
+            "app.services.provider_router.text_to_speech",
+            new_callable=AsyncMock,
+        ) as mock_tts:
+            mock_tts.side_effect = Exception("TTS provider timeout")
+
+            response = auth_client.post(
+                f"/api/stories/{test_story.id}/assets/retry",
+                json={"assets": ["audio"]},
+            )
+
+        assert response.status_code == 200
+        data = response.json()
+        assert data["generation_status"] == "degraded_completed"
+        assert data["image_status"] == "not_requested"
+        assert data["audio_status"] == "failed"
+        assert "TTS provider timeout" in data["last_error"]
+
     def test_retry_audio_on_storybook_is_rejected(
         self,
         auth_client: TestClient,