Testnizer v1.4.13

v1.4.13

macOS builds are now signed with an Apple Developer ID and notarized by
Apple — no more "unidentified developer" / "app is damaged" Gatekeeper block,
and in-app auto-update now works on macOS too.

• macOS — signed & notarized: every macOS build is now code-signed with a
  Developer ID Application certificate and notarized through Apple's notary
  service, with the hardened runtime enabled. Gatekeeper opens the app directly
  — no right-click → Open workaround, and no "app is damaged and can't be
  opened" error on Apple Silicon. spctl reports the app as
  "Notarized Developer ID".
• macOS — auto-update: because builds are now notarized, in-app automatic
  updates work on macOS as well (previously macOS users were routed to a manual
  download, issue #34).
• Quality: the automated test layer grew to 679 UI E2E tests (163 spec
  files, parallel-stable at 4 workers) and 1696 unit tests after a
  manual-checklist coverage sweep — new journeys cover header autocomplete,
  the resolved actual-request view, auth-type selection, mock CORS and proxy
  recording, Insomnia export, PFX/PKCS12 certificates and suite-item rename.

No functional changes to requests, protocols or data — this release is about
trust (signing) and verification (tests). Windows signing is still in progress.