dsh-mac-control: macOS Local Control Tool for DeepSeek Harness

`dsh-mac-control` is a native macOS plugin for DeepSeek Harness that enables agents to directly operate the local desktop environment. It provides two tool categories: `mac_browser` (controls browser tabs) and `mac_desktop` (operates applications, windows, and captures screenshots). The plugin is built on native macOS capabilities and does not depend on HTTP services or proxies. Secure defaults include allowlisted addresses, sensitive-data validation, and strict permission management. After installation, users must restart their profile and grant the relevant permissions in the system to securely perform cross-application control and interaction.