Consolidate set_meta into update_document (#14045)

### What problem does this PR solve?

Consolidate "set_meta" API into "update_document" .

Before consolidation
Web API: POST /api/v1/document/set_meta
Http API - PUT /v1/datasets/<dataset_id>/document/<document_id>

After consolidation, Restful API -- PUT
/v1/datasets/<dataset_id>/document/<document_id>

### Type of change

- [x] Refactoring

admin/client/ragflow_client.py

@@ -1564,6 +1564,28 @@ class RAGFlowClient:
         else:
             print(f"Fail to update chunk, HTTP {response.status_code}")
 
+    def _get_documents_by_ids(self, ids:list[str]):
+        response = self.http_client.request(
+            "POST",
+            "/document/infos",
+            json_body={"doc_ids": ids},
+            use_api_base=False,
+            auth_kind="web"
+        )
+
+        if response.status_code != 200:
+            return f"Fail to get document info, HTTP {response.status_code}", None
+
+        res_json = response.json()
+        if res_json.get("code") != 0:
+            return f"Fail to get document info: {res_json.get('message')}", None
+
+        docs = res_json.get("data", [])
+        if not docs:
+            return f"Document not found: {ids}", None
+
+        return None, docs
+
     def set_metadata(self, command_dict):
         if self.server_type != "user":
             print("This command is only allowed in USER mode")
@@ -1572,14 +1594,42 @@ class RAGFlowClient:
         doc_id = command_dict["doc_id"]
         meta_json_str = command_dict["meta"]
 
+        # Parse JSON string to dict
+        import json
+        try:
+            meta_fields = json.loads(meta_json_str)
+        except json.JSONDecodeError as e:
+            print(f"Invalid JSON format: {e}")
+            return
+
+        # Step 1: Get document info to find kb_id (dataset_id)
+        doc_error_msg, docs = self._get_documents_by_ids([doc_id])
+        if doc_error_msg:
+            print(doc_error_msg)
+            return
+
+        if len(docs) == 0:
+            print(f"no document found for {doc_id}")
+            return
+
+        dataset_id = docs[0].get("kb_id")
+        if not dataset_id:
+            print(f"Dataset ID not found for document: {doc_id}")
+            return
+
         # Send meta as JSON string
         payload = {
-            "doc_id": doc_id,
-            "meta": meta_json_str,
+            "meta_fields": meta_fields,
         }
 
-        response = self.http_client.request("POST", "/document/set_meta", json_body=payload,
-                                            use_api_base=False, auth_kind="web")
+        response = self.http_client.request(
+            "PUT",
+            f"/datasets/{dataset_id}/documents/{doc_id}",
+            json_body=payload,
+            use_api_base=True,
+            auth_kind="web"
+        )
+
         res_json = response.json()
         if response.status_code == 200:
             if res_json.get("code") == 0: