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/user.py

@@ -0,0 +1,65 @@
+#
+#  Copyright 2025 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 http_client import HttpClient
+
+
+class AuthException(Exception):
+    def __init__(self, message, code=401):
+        super().__init__(message)
+        self.code = code
+        self.message = message
+
+
+def encrypt_password(password_plain: str) -> str:
+    try:
+        from api.utils.crypt import crypt
+    except Exception as exc:
+        raise AuthException(
+            "Password encryption unavailable; install pycryptodomex (uv sync --python 3.12 --group test)."
+        ) from exc
+    return crypt(password_plain)
+
+
+def register_user(client: HttpClient, email: str, nickname: str, password: str) -> None:
+    password_enc = encrypt_password(password)
+    payload = {"email": email, "nickname": nickname, "password": password_enc}
+    res = client.request_json("POST", "/user/register", use_api_base=False, auth_kind=None, json_body=payload)
+    if res.get("code") == 0:
+        return
+    msg = res.get("message", "")
+    if "has already registered" in msg:
+        return
+    raise AuthException(f"Register failed: {msg}")
+
+
+def login_user(client: HttpClient, server_type: str, email: str, password: str) -> str:
+    password_enc = encrypt_password(password)
+    payload = {"email": email, "password": password_enc}
+    if server_type == "admin":
+        response = client.request("POST", "/admin/login", use_api_base=True, auth_kind=None, json_body=payload)
+    else:
+        response = client.request("POST", "/user/login", use_api_base=False, auth_kind=None, json_body=payload)
+    try:
+        res = response.json()
+    except Exception as exc:
+        raise AuthException(f"Login failed: invalid JSON response ({exc})") from exc
+    if res.get("code") != 0:
+        raise AuthException(f"Login failed: {res.get('message')}")
+    token = response.headers.get("Authorization")
+    if not token:
+        raise AuthException("Login failed: missing Authorization header")
+    return token