Refactor system/version API to RESTful style (#13956)

### What problem does this PR solve?

Refactor version API to RESTful style. Python and go server API also
updated.
### Type of change

- [x] Refactoring



<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

## Release Notes

* **Refactor**
* Migrated core API endpoints to the `/api/v1/` namespace for improved
consistency and organization.
* Standardized system version, search, and chat list endpoints under the
new API versioning structure.

* **New Features**
* Added MinIO region configuration support, allowing specification of
storage engine regional settings via environment variables or
configuration files.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

api/apps/restful_apis/system_api.py

@@ -0,0 +1,42 @@
+#
+#  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+from api.apps import login_required
+
+from api.utils.api_utils import get_json_result
+from common.versions import get_ragflow_version
+
+@manager.route("/system/version", methods=["GET"])  # noqa: F821
+@login_required
+def version():
+    """
+    Get the current version of the application.
+    ---
+    tags:
+      - System
+    security:
+      - ApiKeyAuth: []
+    responses:
+      200:
+        description: Version retrieved successfully.
+        schema:
+          type: object
+          properties:
+            version:
+              type: string
+              description: Version number.
+    """
+    return get_json_result(data=get_ragflow_version())

api/apps/system_app.py

@@ -29,7 +29,6 @@ from api.utils.api_utils import (
     server_error_response,
     generate_confirmation_token,
 )
-from common.versions import get_ragflow_version
 from common.time_utils import current_timestamp, datetime_format
 from common.log_utils import get_log_levels, set_log_level
 from timeit import default_timer as timer
@@ -39,30 +38,6 @@ from quart import jsonify
 from api.utils.health_utils import run_health_checks, get_oceanbase_status
 from common import settings
 
-
-@manager.route("/version", methods=["GET"])  # noqa: F821
-@login_required
-def version():
-    """
-    Get the current version of the application.
-    ---
-    tags:
-      - System
-    security:
-      - ApiKeyAuth: []
-    responses:
-      200:
-        description: Version retrieved successfully.
-        schema:
-          type: object
-          properties:
-            version:
-              type: string
-              description: Version number.
-    """
-    return get_json_result(data=get_ragflow_version())
-
-
 @manager.route("/status", methods=["GET"])  # noqa: F821
 @login_required
 def status():