[deverman]

Summary

• replace the legacy exporter with a validated Ulysses 40 to FSNotes/TextBundle migration engine
• preserve sheets, groups, order, sidebar metadata, images, attachments, dates, archive roles, Inbox, and Trash with visible fidelity reports
• add a guided macOS app, CLI preflight/doctor workflow, privacy-safe support bundle, and defensive format fingerprinting
• add a sandboxed App Store target, production icon, tested Swift release tooling, and ARM/Intel CI/release workflows
• split exporter responsibilities into focused reader, layout, rendering, reporting, and per-sheet modules

Validation

• swift test: 35 tests pass
• private Ulysses 40 smoke test: 2,631-sheet backup passes
• clean detached worktree: tests pass and universal Release App Store target builds
• unsigned ARM64 and x86_64 release ZIPs build with correct architectures, icons, versions, and SHA-256 files

Remaining external release gates

• GitHub Actions must run when repository visibility/settings permit
• signed/notarized workflow needs Apple Developer ID and notarization secrets
• final screenshots and downloaded-artifact Gatekeeper test happen after signed packaging