Version embed goes stale post-GA; skew warning tells up-to-date users to downgrade

[coderdan]

Summary

Follow-up closing the one #666 review finding deliberately left out of that PR: post-GA staleness of the version embed. Two related gaps:

1. Stale embed. stash has no publishable dependency edge to the runtime packages, so a runtime-only release would not republish stash. The live CLI tarball keeps embedding (and init keeps pinning/recommending) outdated versions.
2. Directionless skew. versionSkew is a bare !== with no direction, so the skew warning tells users on correctly-newer versions to downgrade.

Expected

• Any release should republish the whole release train so the embed can never go stale against the packages it pins.
• Skew detection should be direction-aware: behind → align/reinstall guidance; ahead → recommend updating the stash CLI, never a downgrade. Malformed/unreadable versions should be treated as not-comparable → safe reinstall guidance.

Resolution

Fixed in #669:

• Changesets fixed group couples the release train (stash, @cipherstash/stack, @cipherstash/stack-drizzle, @cipherstash/stack-supabase, @cipherstash/prisma-next, @cipherstash/wizard) in lockstep, with a test asserting fixed group == RELEASE_TRAIN_MANIFESTS.
• Direction-aware skew via a prerelease-aware comparator with a strict shape gate (closes the whole malformed-version family), plus direction-aware skills/stash-cli skew guidance.

[coderdan]

Resolved by #669 (merged).