[Fail-Safe]

Summary

• Adds a small Omarchy menu backport so Vivaldi appears under Install → Browser, Remove → Browser, and Setup → Default Browser.
• Completes the UX gap left by feat: add signed Vivaldi ARM64 installer #80: the signed ARM64 installer existed, but there was no menu entry to launch it.
• Pins patch digests and extends verify.py contract coverage for the three menu IDs.

Test plan

• python3 guest/tests/verify.py (backport metadata / digests)
• Optional: python3 guest/tests/verify.py --source <pinned-omarchy-checkout> to exercise staged menu postimage checks
• In an aarch64 guest: Omarchy menu → Install → Browser → Vivaldi launches the existing ARM64 installer path
• After install: Default Browser → Vivaldi and Remove → Browser → Vivaldi appear as expected
• Confirm Chromium/Firefox/Zen menu rows are unchanged

[themartiano]

Thanks for the pull request!

Codex comments

The menu entries connect to the existing ARM64 installer/default/removal paths. Verified the pinned upstream backport and combined tests.