UltraConvert 1.6.0 — notarized macOS preview

UltraConvert 1.6.0 is a native macOS preview focused on helping new users find and understand conversion, Finder actions and folder rules.

• A four-topic Getting Started guide opens on an empty first launch and links directly to the relevant task. Settings and help are visible in the converter.
• Numbered conversion stages and advice for all 62 formats explain the next step and format tradeoffs.
• Folder rules retain their setup checklist, explain ALL/ANY matching and stable-file waiting, show unsaved changes, and provide selectable full preview details. Editing invalidates old plans; Discard restores Archive acknowledgement.
• Mixed-file context shortcuts require a compatible target for every selected file. An incompatible Finder preset waits for an explicit compatible choice before enabling Convert.
• Finder Quick Actions, format Services and optional startup registration have separate, clearer setup instructions and truthful status messages. Finder icons use the canonical ICNS artwork; automatic setup only runs from system/user Applications folders, so test archives cannot redirect installed actions.

The native app in the installer ZIP is signed with Developer ID Application and Apple notarized, with its ticket stapled and Gatekeeper assessment checked. Conversion engines remain a separate installation: keep the extracted UltraConvert folder together and run python3 install.py after installing Homebrew. The prebuilt .app alone does not provision its runtime. See README.md and INSTALL-FIRST.txt in the ZIP.

Validation: 305 native folder-rule assertions, guidance/layout/backend regressions, installer rollback/signature checks, 22 release tests, representative round trips for every listed format, preservation/security/batch tests and successful GitHub CI on the frozen app-code commit. A final programmatic controller/engine check passed 33 assertions for real WAV→MP3 and PNG→WebP recognition/conversion, direct sibling placement, collision retention, accurate results/reports and queue clearing. The exact notarized app installed on the maintainer's Mac then passed actual mixed-file conversion and an independent full rule-preview crawl, including read-only/selectable details, edit invalidation and safe discard/cleanup. Existing separate-runtime engines also passed all 62 round trips, 14 preservation checks, 10 edge checks, 18 security tests and 13 batch tests against extracted release source. The coding-agent first-use assessment improved from 7.9 to 9.0/10; this is a scoped developer assessment, not a human user study or a guarantee for every input. Older macOS/Intel, manual VoiceOver and actual login activation remain unverified.

This is a prerelease. Stable v1.3.0 remains the default release. The complete bundled-engine development app stays local while its corresponding-source/licence and complete-bundle distribution checks are unfinished. RELEASE-METADATA.json and SHA256SUMS.txt describe the exact public artifacts.