UltraConvert 1.5.1 Preview — Native polish and safer editing

UltraConvert 1.5.1 refines native folder automation and Finder conversion with safer rule editing, cancellable file tests and standard Mac keyboard controls.

• Rule navigation and closing now offer Save Changes, Keep Editing and Discard Changes. Discard restores the saved rule, including text still being edited; invalid enabled-rule saves keep the editor open.
• Read-only file tests can be cancelled. Late results cannot overwrite feedback after edits, rule switches or closing, and quit waits for cleanup. Test previews use the same source and companion-file protections as conversion.
• Native Undo, Redo, Cut and Close Window shortcuts, plus Cancel/Escape in the Finder grouped-format picker. Explicit app-controller retention keeps actions responsive in optimized builds.
• Reused Activity rows reset completely and share cached date formatting. The neutral native macOS glass design remains free of coloured block-edge accents.

Validation: 265 local automation assertions, real content recognition and conversion, native layout/backend checks, installer rollback/signature checks, static security/dependency audits, and installed-app keyboard/save/discard/Settings/Finder cancellation checks on Apple Silicon with macOS 27. The scoped developer UX review remains 9.0/10; independent usability, VoiceOver and older-system validation remain open. See docs/UX-AUDIT.md and evidence/automation-1.5.1.json.

Preview installation: download the macOS arm64 ZIP, keep its complete folder together and run python3 install.py following README.md. The DMG contains the same installer folder. Conversion engines are installed separately; the prebuilt app alone is not a standalone installer. This preview is ad-hoc signed and not Apple notarized. If macOS blocks it, use the documented build-from-source route without disabling Gatekeeper.

Finder Services and Quick Actions remain flat under macOS control. The Choose Format service opens UltraConvert's grouped category/format picker; nested category menus are also available inside the app. This release does not ship a Finder Sync extension.

The complete local development app retains all engines and remains unpublished pending dependency-source/licence review and Developer ID/notarization. This preview does not replace stable v1.3.0.

Released commit: 2715ebadac3ad5ea10bccfd5b523e2f8ad073fa4. GitHub CI: static audit and macOS conversion/native UI/security/rollback checks.