Add authentication features for admin access

- Introduce a new `auth` module with login, logout, and user verification endpoints for a single admin user.
- Update backend routes to require admin authentication for sensitive operations, enhancing security.
- Modify frontend components to include an authentication provider and gate, ensuring only authorized users can access the application.
- Implement a login page for admin access, improving user experience and security management.
- Update API request handling to redirect unauthorized users to the login page, ensuring proper access control.

deploy/README.md

@@ -94,12 +94,15 @@ uv run --with-requirements requirements.txt \
 
 ### 4. 单独启动前端
 
-前端也监听 `0.0.0.0`。`NEXT_PUBLIC_API_BASE_URL` 要写浏览器最终访问 nginx 的
-https 地址,不要写 `:8000`:
+前端也监听 `0.0.0.0`。`NEXT_PUBLIC_API_BASE_URL` 只有一个规则:
+**写浏览器地址栏里访问 nginx 的同源地址**。如果地址栏带端口,这里也必须带端口;
+如果地址栏不带端口,这里也不带端口。不要写后端直连端口 `:8000`。
 
 ```bash
 cd frontend
 npm install
+
+# nginx 使用默认 443 时:
 NEXT_PUBLIC_API_BASE_URL=https://<远程机器IP或域名> \
   npm run dev -- --hostname 0.0.0.0
 ```
@@ -146,7 +149,7 @@ docker run --rm --name ai-video-nginx \
 访问:
 
 ```text
-https://<远程机器IP或域名>
+https://<远程机器IP或域名>:18189
 ```
 
 ### 6. 远程语音 / WebRTC 注意事项
@@ -174,11 +177,13 @@ TURN_SECRET=<同上>
 
 ## 前端怎么连后端
 
-前端读环境变量 `NEXT_PUBLIC_API_BASE_URL`(compose 里已设)。走 nginx 后,
-让它指向**同源**即可,ws 地址由它推导:
+前端读环境变量 `NEXT_PUBLIC_API_BASE_URL`。走 nginx 后,让它等于浏览器访问
+页面的 **origin** 即可。origin 包含协议、host 和可选端口:
 
 ```
-NEXT_PUBLIC_API_BASE_URL = https://<访问用的host>      # 同源,不再写 :8000
+默认 443:   NEXT_PUBLIC_API_BASE_URL=https://<访问用的host>
+自定义端口: NEXT_PUBLIC_API_BASE_URL=https://<访问用的host>:18189
+
 wsUrl = NEXT_PUBLIC_API_BASE_URL.replace(/^http/, 'ws') + '/ws/voice'
 ```