[1.58.1] - 2026-08-03

Small macOS app release: the menu-bar footer no longer shows a stale,
hand-edited build stamp. It now reads the actually-installed vaara engine
version from vaara --version at runtime, so the on-screen version always
matches the binary regardless of how the app was installed (IDE/XcodeGen,
Homebrew, or a copied /Applications build). The GitHub update-check
User-Agent is derived from the same live version instead of a hardcoded
1.56.0.

Fixed

• macOS app footer shows the live installed engine version (was a frozen
  BUILD_STAMP constant that predated the release).
• checkForUpdates sends User-Agent: VaaraMenuBar/<installed> instead of a
  hardcoded 1.56.0.
• Bumped BUILD_STAMP to b57 · 2026-08-03.