feat: add generation trace and partial-ready workflow status

backend/tests/conftest.py

@@ -66,7 +66,8 @@ async def test_story(db_session: AsyncSession, test_user: User) -> Story:
         story_text="从前有一只小兔子。",
         cover_prompt="A cute rabbit in a forest",
         mode="generated",
-        generation_status="narrative_ready",
+        generation_status="partial_ready",
+        text_status="ready",
         image_status="not_requested",
         audio_status="not_requested",
     )
@@ -102,6 +103,7 @@ async def storybook_story(db_session: AsyncSession, test_user: User) -> Story:
         image_url="https://example.com/storybook-cover.png",
         mode="storybook",
         generation_status="degraded_completed",
+        text_status="ready",
         image_status="failed",
         audio_status="not_requested",
         last_error="第 2 页插图生成失败",
@@ -123,6 +125,7 @@ async def degraded_story_with_text(db_session: AsyncSession, test_user: User) ->
         cover_prompt="A rabbit under the moon",
         mode="generated",
         generation_status="degraded_completed",
+        text_status="ready",
         image_status="failed",
         audio_status="not_requested",
         last_error="封面生成失败",