dsh-browser-tool: DSH Browser Tool

DSH (DeepSeek Harness)'s browser tool `dsh-browser-tool` adopts an "everything is a plugin" architecture. Its core components support a three-stage `open`/`run`/`close` workflow, and it provides headless, spawned, connected, and relay modes for driving Chromium. The tool has been archived, with development migrated to `mtaech/melon`. Installation requires registering it to the Profile, configuring the `sharp` build script, and paying attention to how `peerDependencies` are used. It supports script execution, screenshots, and a rich tab API, controls behavior via environment variables, and reuses the Chromium cache using a specific strategy.