dsh-workspace-insight: Add a Workspace/Session Activity Dashboard to DSH Web UI

dsh-workspace-insight is a DSH client plugin maintained by stone-beka that adds a read-only, purely local workspace/session activity dashboard to the Web UI. It offers three views: an Overview that displays workspace usage, session count, rounds, time spent on models and tools, and today's heatmap, marking workspaces unused for over 20 days with remaining sessions as "Suggest Archive"; a Monthly view that visualizes the activity of each workspace segmented by day; and a Timeline view, a continuous date matrix with rows representing dates and columns representing workspaces, supporting panning and zooming. Data is read-only, sourced from `workspace.json`, projection cache, and `.zstd` session logs under `$DSH_HOME`, making no network requests (the only write operation is the daily active index cache). Installation uses the package name `dsh-workspace-insight` via the CLI command `dsh plugin --profile web add`; for the desktop version, use the settings interface as the desktop profile cannot be installed via the terminal. It is compatible with DSH 0.2.2-rc.1 and requires Node.js ≥ 20. License: MIT. The article explains troubleshooting for installation errors, data definitions, and use cases, and provides a table of contents and a GitHub link.