修复回忆录图片重试状态透传与前端展示

api/routers/chapters.py

@@ -21,7 +21,9 @@ from services.memoir_images.schema import (
 )
 from services.memoir_images.settings import MemoirImageSettings
 from services.memoir_images.storage import (
+    CosDownloadUrlError,
     TencentCosStorageService,
+    mark_image_delivery_unavailable,
     normalize_cos_url,
     resolve_image_storage_key,
 )
@@ -53,10 +55,15 @@ def _normalize_image_assets(images: list[dict] | None) -> list[dict]:
         if asset.get("status") == IMAGE_STATUS_COMPLETED and storage_key:
             try:
                 asset["url"] = storage.get_download_url(storage_key)
+            except CosDownloadUrlError as exc:
+                logger.warning(
+                    "章节图片签名失败: key=%s, retryable=%s, request_id=%s, error=%s",
+                    storage_key, exc.retryable, exc.request_id, exc,
+                )
+                asset = mark_image_delivery_unavailable(asset)
             except Exception as exc:
                 logger.warning("章节图片签名失败: key=%s, error=%s", storage_key, exc)
-                asset["url"] = normalized_url
-                asset["error"] = asset.get("error") or "image delivery unavailable"
+                asset = mark_image_delivery_unavailable(asset)
         else:
             asset["url"] = normalized_url
         asset.pop("storage_key", None)