fix: trigger the real macOS Accessibility prompt instead of bouncing to Settings

[Alfredoalv13]

Summary

• Same root cause as fix: trigger the real macOS Screen Recording prompt instead of bouncing to Settings #12 (Screen Recording), for Accessibility: `getAccessibilityPermissionStatus()` uses `isTrustedAccessibilityClient(false)`, a passive read that never prompts or registers the app in System Settings.
• `requestAccessibilityPermission()` (`isTrustedAccessibilityClient(true)`) already existed in the backend/preload but was never called from the actual recording flow - `startStudioRecording` jumped straight to `openAccessibilityPreferences()` when not trusted.
• Verified directly this session: even after correctly granting Screen Recording (via fix: trigger the real macOS Screen Recording prompt instead of bouncing to Settings #12's fix) and toggling what appeared to be the right Accessibility entry in System Settings, followed by a full quit-and-reopen, the app kept reporting Accessibility as not granted - because the real request path was never exercised, only the passive check.

Test plan

• `tsc --noEmit` clean
• `npm test` - 94/94 files, 819/819 tests passing (added coverage for the not-trusted -> prompt -> trusted path)
• Manual: on a fresh install where VybeClip has never appeared in Accessibility settings at all, click Record and confirm the real macOS "would like to control this computer" prompt now appears