[AmethystLiang]

Summary

• add a main-process test that verifies automatic update checks reschedule 36 hours after update-available
• add a renderer hook test that verifies updater status events update store state and drive the in-app update notification toast
• run the focused updater/notification vitest suite

Testing

• pnpm exec vitest run --config config/vitest.config.ts src/main/updater.test.ts src/main/updater.check-failure.test.ts src/renderer/src/hooks/update-toast-controller.test.ts src/renderer/src/hooks/useIpcEvents.test.ts