Add HTTPS demo entry for microphone access

- Add a self-signed HTTPS Nginx entrypoint on Docker port 4443 so browser microphone APIs can run in demo mode.

- Keep the existing HTTP port 4002 unchanged while exposing container port 443 and generating the demo certificate during image build.

- Update CORS defaults and Compose environment for the HTTPS frontend origin.

- Clarify the report editor microphone message with localhost, HTTPS, and browser trusted-origin demo options.

- Document the browser HTTP microphone limitation, HTTPS demo URL, and Chrome/Edge insecure-origin workaround in README and docs.

README.md

@@ -223,6 +223,7 @@ docker-compose up -d --build
 
 ```text
 前端: http://localhost:4002
+语音 HTTPS 演示入口: https://localhost:4443
 API:  http://localhost:3002/api/health
 数据库: localhost:5433
 ```
@@ -236,6 +237,7 @@ docker-compose down
 部署说明：
 
 - `web` 服务使用 Nginx 托管前端 `dist/`。
+- Docker 前端同时暴露 `http://localhost:4002` 和自签名证书的 `https://localhost:4443`；麦克风听写建议使用 HTTPS 演示入口。
 - `api` 服务运行 NestJS 后端，并把上传文件目录挂载到 `uploads_data` volume。
 - `db` 服务运行 PostgreSQL 16。
 - `nginx.conf` 已配置 SPA 路由回退、`/api` 反向代理和 `100m` 请求体上限。