Add auto-update flow for new app releases

[robdefeo]

Summary

• add Tauri updater command wiring and release-check logic
• integrate updater state into app/system state and UI surfaces
• expose update controls/status in Settings and related pages

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

[benjaminshafii]

Automated review from OpenWork enterprise bot 🤖

Requested changes

1. Add a timeout + fallback for prerelease checks (GitHub API rate limits/latency can stall the UI). If the prerelease API fails, fall back to stable or surface a fast error state.
2. Invalidate pending updates on channel change (or store the channel with the pending update and block mismatched downloads). This avoids downloading a prerelease after switching to stable.
3. Avoid holding the full update payload in memory. If the updater API only supports byte installs, add a hard cap/guard and error message; otherwise stream to disk or use the updater’s built-in install path.

Testing request

• Include a screenshot of Settings → Updates showing the channel toggle and update status (checking/downloading/ready or restart-required).
• Note how you tested the flow.

[benjaminshafii]

Thanks for the @robdefeo

[robdefeo]

I'm going to close this, I now see there is already auto update checking. Thanks for the review