feat：新增大屏存取发布接口

app/api/files.py

@@ -85,9 +85,13 @@ class UploadSizeLimit:
         return None
 
 
+def _public(record: DataFileRecord) -> dict:
+    return {**record.model_dump(), "pinned": bool(record.pinned_by)}
+
+
 def _detail(record: DataFileRecord) -> DataFileDetail:
     # 按接口模型重新校验，去掉 owner_id、sha256、列概况等只在后端用的字段
-    return DataFileDetail.model_validate(record.model_dump())
+    return DataFileDetail.model_validate(_public(record))
 
 
 @limits_router.get("/limits")
@@ -130,9 +134,7 @@ async def list_files(
     records = await service.list_files(user.id, conversation_id)
     return success_response(
         DataFileList(
-            files=[
-                DataFileInfo.model_validate(record.model_dump()) for record in records
-            ],
+            files=[DataFileInfo.model_validate(_public(record)) for record in records],
             uploads=service.list_uploads(user.id, conversation_id),
         )
     )