Name the executable in each update zip after its bundle

[thesiti92]

Why

Squirrel renames an install to the update's CFBundleExecutable, not to the zip's folder name (SQRLInstaller renamedTargetIfNeededWithTargetURL: compares the installed folder name with the update's executable name). The Review zip from #549 carries Review.app whose executable is still Whiteboard, so a 0.0.33 Review.app updating to 0.0.34 was renamed to Whiteboard.app, the Dock tile broke, and ShipIt's relaunch failed at the old path. Seen on a real 0.0.33 → 0.0.34 update today.

The runner smoke run passed because its starting copy (the .59 Review zip) already had mismatched executable and folder names, which turns the rename off before that comparison runs. It did not model a genuine pre-rename install.

What changes

• notarize-macos.sh: for each zip whose bundle name differs from the build's, rename Contents/MacOS/<exe>, set CFBundleExecutable, re-sign the outer bundle with the same identity and app.plist entitlements (nested helpers and frameworks keep their signatures), verify, then notarize and staple that copy on its own before zipping. One build, one extra notarization per extra zip.
• validate-release-artifacts.mjs: assertZipBundle now also reads each zip's Info.plist and fails when the executable name differs from the bundle name. Against the published 0.0.34 Review zip it fails with the exact message; against a fixed copy it passes.
• Comments and README say "executable name" instead of "folder name".

Validation

• Script tests: 25 pass. pnpm lint, oxfmt, shellcheck, bash -n.
• Dry run on the real 0.0.34 Review zip: after the executable rename and an outer-bundle-only re-sign, codesign --verify --deep --strict passes and nested code retains its team identity.
• Needs a preview release to prove the signed, notarized copy end to end from an install whose executable and folder names match (e.g. preview .56 or stable 0.0.33).

Fixes the rename for every remaining Review.app install once 0.0.35 ships. Installs already renamed to Whiteboard.app by 0.0.34 are unaffected either way.