dsh-web-lan: DeepSeek Harness LAN Access Layer

`dsh-web-lan` is a LAN access plugin for the DeepSeek Harness (DSH) Web service, maintained by developer yes8080. It wraps request handling to address compatibility issues in HTTP-only LAN environments, provides a password-based login gate and access control, supports managing the password directly in the Web UI, and fixes errors related to `crypto.randomUUID` and the client `isLoopback`. After installation, the service listens on a local network address (default port 3080) with a default password of `123`. Because passwords and data are transmitted in plaintext over HTTP, it is suitable only for trusted LAN environments. Change the password immediately after installation or override it via an environment variable. To remove it, uninstall the plugin through a command and clean up any leftover data.