feat: polish generation demo workflow

backend/tests/test_stories.py

@@ -9,6 +9,14 @@ from app.core.config import settings
 from app.services.adapters.storybook.primary import Storybook, StorybookPage
 
 
+def assert_legacy_generation_headers(response, successor: str) -> None:
+    """Assert that compatibility generation endpoints point callers to the unified API."""
+
+    assert response.headers["Deprecation"] == "true"
+    assert response.headers["X-DreamWeaver-Successor-Endpoint"] == successor
+    assert response.headers["Link"] == f'<{successor}>; rel="successor-version"'
+
+
 def build_storybook_output() -> Storybook:
     """Create a reusable mocked storybook payload."""
 
@@ -62,6 +70,7 @@ class TestStoryGenerate:
             json={"type": "keywords", "data": "小兔子, 森林, 勇气"},
         )
         assert response.status_code == 200
+        assert_legacy_generation_headers(response, "/api/generations")
         data = response.json()
         assert "id" in data
         assert "title" in data
@@ -317,6 +326,7 @@ class TestGenerateFull:
             json={"type": "keywords", "data": "小兔子, 森林, 勇气"},
         )
         assert response.status_code == 200
+        assert_legacy_generation_headers(response, "/api/generations")
         data = response.json()
         assert "id" in data
         assert "title" in data
@@ -394,6 +404,7 @@ class TestUnifiedGenerations:
         )
 
         assert response.status_code == 200
+        assert "Deprecation" not in response.headers
         data = response.json()
         assert data["id"] is not None
         assert data["mode"] == "generated"
@@ -534,6 +545,10 @@ class TestImageGenerateSuccess:
     ):
         response = auth_client.post(f"/api/image/generate/{test_story.id}")
         assert response.status_code == 200
+        assert_legacy_generation_headers(
+            response,
+            f"/api/generations/{test_story.id}/retry-assets",
+        )
         data = response.json()
         assert data["image_url"] == "https://example.com/image.png"
         assert data["generation_status"] == "completed"
@@ -557,6 +572,10 @@ class TestAssetRetry:
         )
 
         assert response.status_code == 200
+        assert_legacy_generation_headers(
+            response,
+            f"/api/generations/{degraded_story_with_text.id}/retry-assets",
+        )
         data = response.json()
         assert data["image_url"] == "https://example.com/image.png"
         assert data["generation_status"] == "completed"
@@ -585,6 +604,10 @@ class TestAssetRetry:
             )
 
         assert response.status_code == 200
+        assert_legacy_generation_headers(
+            response,
+            f"/api/generations/{storybook_story.id}/retry-assets",
+        )
         data = response.json()
         assert data["generation_status"] == "completed"
         assert data["image_status"] == "ready"