dsh-douyin-mac: Google Chrome-only Douyin DSH Plugin for macOS

`dsh-douyin-mac` ports the upstream `dsh-douyin-agent` 1.4.6 into a DSH plugin form that runs exclusively Google Chrome on macOS. Settings are accessed via "Settings → Douyin Browsing," and status and memory are saved in `~/.dsh/douyin-browser/`. Verified capabilities include autonomous viewing (time slots and daily minutes/model request quotas), persona and interest memory, permission-based friend interaction and group chat replies, self-sharing of official panels, independently toggleable public comments, silent watching, optional audio via local Whisper or MiMo/MiniMax, and a daily viewing report generated from local logs. It also includes JPEG storyboard sampling with a 480,000 pixel budget and reading of `douyin_video_zoom` original images. The installation command is `dsh plugin --profile web add dsh-douyin-mac@0.1.15`, with an alternative installation method using the source code directory. It comes with a data editing script (default preview, save only with `--apply`, may trigger SMS verification). First-time use involves a four-step configuration for the model, login, viewing schedule, and permission sessions. The README explicitly marks the third-party adaptation identity, the location of macOS real-device verification records, and boundaries where recommended feed switching failures, real public comment confirmation, continuous two-hour playback, and real group chat multi-recipient sharing are still pending verification.