Pull-request activity notifications

Desktop Material raises operating-system notifications for relevant pull request review submissions, issue/review comments, and failed checks received through its live provider event channel. Titles identify the actor/event and the bounded body identifies the known pull request without exposing a token or raw provider response.

Notifications are intentionally scoped to the selected GitHub repository and pull requests already known to the local coordinator. Fork contribution mode maps events to the configured parent or fork repository. Clicking a notification revalidates its cached repository/PR context and opens the matching review, comment, or checks workflow in Desktop Material.

Missing accounts, unknown PRs/comments/reviews, invalid review states, unrelated repositories, and unsuccessful provider lookups are ignored rather than displaying an unactionable alert. Failed-check notifications require a commit authored by the bound account and de-duplicate check runs/suites so re-delivered events do not spam the user.

The event payload is passed as operating-system notification user data only for the activation route; credentials are never included. The renderer/main-process bridge uses the platform notification implementation and a testable fallback.

Verification includes the notifications store/debug store, valid-review, check-status, main-process notification bridge, and notification dialog suites.