chore: version packages

[omermorad]

Summary

• Reuse the release branch already created by Prepare Release, without rerunning version preparation or rewriting history.
• Prepare all seven public Contractual packages as 0.1.0-beta.0, with generated package changelogs.
• Target next; this PR does not tag or publish anything.

Verification

• Preparation completed installation, build, unit tests, and E2E tests before versioning.
• The workflow failed only when creating the PR because Actions PR creation was disabled.
• PR checks must now validate the prepared version commit before review and merge.

Release gates

• CI retains only the two approved temporary advisory exceptions, expiring at 2026-10-22 05:37:00 UTC.
• The publishing workflow still uses its strict audit gate. No release-time exception is approved by this PR.
• Omer must separately approve the exact publication commit, package versions, and any tag or release operation.
• After an approved Contractual publication, update and rebuild contractual-action against the published betas through its own PR to next.