Fix: add file convert backward compatibility (#14583)

### What problem does this PR solve?

add file convert backward compatibility

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/apps/backward_compat.py

@@ -26,6 +26,7 @@ Deprecated APIs and their replacements:
 - POST /api/v1/chats_openai/{chat_id}/chat/completions -> POST /api/v1/openai/{chat_id}/chat/completions
 - PUT /api/v1/chats/{chat_id}/sessions/{session_id} -> PATCH /api/v1/chats/{chat_id}/sessions/{session_id}
 - DELETE /api/v1/chats -> DELETE /api/v1/chats/{chat_id} (with body)
+- POST /api/v1/file/convert -> POST /api/v1/files/link-to-datasets
 - GET /api/v1/file/* -> GET /api/v1/files*
 - POST /api/v1/file/* -> POST /api/v1/files*
 - POST /api/v1/sessions/related_questions -> POST /api/v1/chat/recommandation
@@ -36,7 +37,7 @@ import logging
 from quart import Blueprint, request
 
 from api.apps import login_required
-from api.apps.restful_apis import chat_api, file_api, chunk_api, openai_api, document_api
+from api.apps.restful_apis import chat_api, file_api, file2document_api, chunk_api, openai_api, document_api
 from api.apps.restful_apis import agent_api
 from api.apps.services import file_api_service
 from api.utils.api_utils import get_data_error_result, get_json_result, add_tenant_id_to_kwargs
@@ -240,6 +241,22 @@ async def deprecated_file_upload(tenant_id=None):
     return await file_api.create_or_upload(tenant_id=tenant_id)
 
 
+@manager.route("/file/convert", methods=["POST"])
+@login_required
+async def deprecated_file_convert():
+    """
+    Deprecated: Use POST /api/v1/files/link-to-datasets instead.
+
+    Old path: POST /api/v1/file/convert
+    New path: POST /api/v1/files/link-to-datasets
+    """
+    logging.warning(
+        "API endpoint /api/v1/file/convert is deprecated. "
+        "Please use POST /api/v1/files/link-to-datasets instead."
+    )
+    return await file2document_api.convert()
+
+
 @manager.route("/file/mv", methods=["POST"])
 @login_required
 @add_tenant_id_to_kwargs

docs/references/http_api_reference.md

@@ -7430,6 +7430,10 @@ or
 ```bash
 curl --request POST \
      --url http://{address}/api/v1/files/link-to-datasets \
+     --header 'Content-Type: application/json' \
+     --header 'Authorization: Bearer <YOUR_API_KEY>' \
+     --data '{
+          "file_ids": ["file_id_1", "file_id_2"],
           "kb_ids": ["dataset_id_1", "dataset_id_2"]
      }'
 ```