v0.13.0

Add Sentry connector (18) + app-section a11y + Intel Mac build

- New sentry connector (group Dev, error tracking): list projects, list/get
  issues; resolve or ignore issues gated behind Writer; bearer auth; --manifest
  + --test-connection. Wired into workspace, both CI bin-lists, app embed,
  registry (now 18), site, README, JSON-LD. Package sentry-connector, bin sentry.
- Get-the-app review fixes: 44px touch targets + focus-visible on the secondary
  OS links; aria-label so they read as downloads; copy says "the app" not
  "control panel" for consistency.
- Intel Mac: added a macos-13 (x86_64) job to the installer matrix so future
  installers cover Intel Macs (detection cannot tell Intel from Apple Silicon).
- 26 E2E green; app compiles with Sentry embedded.