Phase A: stamp each preview build with a unique monotonic semver prerelease
(<base>-preview.<run_number>) via an ephemeral tauri.conf.json rewrite on the
preview path. Today every preview reported the static 0.3.0, so the updater
never saw a newer version and never delivered preview updates. The prerelease
ordering makes each new preview offer-able and converges to stable when <base>
ships. (Windows MSI ProductVersion strips the prerelease — caveat noted to
verify; mac/linux unaffected.)
Phase B (rollback) is captured as a design spec for review, not implemented:
per-version preview releases + retention, an in-app Preview-builds picker, an
allow_downgrades install path, and the alembic-head data-safety boundary.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
