release/
├─ ExampleApp.msix
├─ ExampleApp.manifest.toml
├─ Release-Note.md
├─ Release-Checklist.md
├─ release.hashmanifest.toml
└─ evidence/
   ├─ install-upgrade-remove/
   ├─ runtime/
   └─ migration/

Migration: detect source schema → backup → transform → update marker → verify.
Backup failure: abort. Unsupported newer schema: refuse to open.