Add more commands to RAGFlow CLI (#12731)

### What problem does this PR solve?

This PR is going to make RAGFlow CLI to access RAGFlow as normal user,
and work as the a testing tool for RAGFlow server.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

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

admin/client/http_client.py

@@ -0,0 +1,161 @@
+#
+#  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.
+#
+
+import time
+import json
+from typing import Any, Dict, Optional, Tuple
+
+import requests
+
+
+class HttpClient:
+    def __init__(
+            self,
+            host: str = "127.0.0.1",
+            port: int = 9381,
+            api_version: str = "v1",
+            api_key: Optional[str] = None,
+            connect_timeout: float = 5.0,
+            read_timeout: float = 60.0,
+            verify_ssl: bool = False,
+    ) -> None:
+        self.host = host
+        self.port = port
+        self.api_version = api_version
+        self.api_key = api_key
+        self.login_token: str | None = None
+        self.connect_timeout = connect_timeout
+        self.read_timeout = read_timeout
+        self.verify_ssl = verify_ssl
+
+    def api_base(self) -> str:
+        return f"{self.host}:{self.port}/api/{self.api_version}"
+
+    def non_api_base(self) -> str:
+        return f"{self.host}:{self.port}/{self.api_version}"
+
+    def build_url(self, path: str, use_api_base: bool = True) -> str:
+        base = self.api_base() if use_api_base else self.non_api_base()
+        if self.verify_ssl:
+            return f"https://{base}/{path.lstrip('/')}"
+        else:
+            return f"http://{base}/{path.lstrip('/')}"
+
+    def _headers(self, auth_kind: Optional[str], extra: Optional[Dict[str, str]]) -> Dict[str, str]:
+        headers = {}
+        if auth_kind == "api" and self.api_key:
+            headers["Authorization"] = f"Bearer {self.api_key}"
+        elif auth_kind == "web" and self.login_token:
+            headers["Authorization"] = self.login_token
+        elif auth_kind == "admin" and self.login_token:
+            headers["Authorization"] = self.login_token
+        else:
+            pass
+        if extra:
+            headers.update(extra)
+        return headers
+
+    def request(
+            self,
+            method: str,
+            path: str,
+            *,
+            use_api_base: bool = True,
+            auth_kind: Optional[str] = "api",
+            headers: Optional[Dict[str, str]] = None,
+            json_body: Optional[Dict[str, Any]] = None,
+            data: Any = None,
+            files: Any = None,
+            params: Optional[Dict[str, Any]] = None,
+            stream: bool = False,
+            iterations: int = 1,
+    ) -> requests.Response | dict:
+        url = self.build_url(path, use_api_base=use_api_base)
+        merged_headers = self._headers(auth_kind, headers)
+        timeout: Tuple[float, float] = (self.connect_timeout, self.read_timeout)
+        if iterations > 1:
+            response_list = []
+            total_duration = 0.0
+            for _ in range(iterations):
+                start_time = time.perf_counter()
+                response = requests.request(
+                    method=method,
+                    url=url,
+                    headers=merged_headers,
+                    json=json_body,
+                    data=data,
+                    files=files,
+                    params=params,
+                    timeout=timeout,
+                    stream=stream,
+                    verify=self.verify_ssl,
+                )
+                end_time = time.perf_counter()
+                total_duration += end_time - start_time
+                response_list.append(response)
+            return {"duration": total_duration, "response_list": response_list}
+        else:
+            return requests.request(
+                method=method,
+                url=url,
+                headers=merged_headers,
+                json=json_body,
+                data=data,
+                files=files,
+                params=params,
+                timeout=timeout,
+                stream=stream,
+                verify=self.verify_ssl,
+            )
+
+
+    def request_json(
+            self,
+            method: str,
+            path: str,
+            *,
+            use_api_base: bool = True,
+            auth_kind: Optional[str] = "api",
+            headers: Optional[Dict[str, str]] = None,
+            json_body: Optional[Dict[str, Any]] = None,
+            data: Any = None,
+            files: Any = None,
+            params: Optional[Dict[str, Any]] = None,
+            stream: bool = False,
+    ) -> Dict[str, Any]:
+        response = self.request(
+            method,
+            path,
+            use_api_base=use_api_base,
+            auth_kind=auth_kind,
+            headers=headers,
+            json_body=json_body,
+            data=data,
+            files=files,
+            params=params,
+            stream=stream,
+        )
+        try:
+            return response.json()
+        except Exception as exc:
+            raise ValueError(f"Non-JSON response from {path}: {exc}") from exc
+
+    @staticmethod
+    def parse_json_bytes(raw: bytes) -> Dict[str, Any]:
+        try:
+            return json.loads(raw.decode("utf-8"))
+        except Exception as exc:
+            raise ValueError(f"Invalid JSON payload: {exc}") from exc