fix: release gate pattern for squash merge

[vreshch]

Summary

• Fix release gate in publish.yml to match squash merge commit messages
• Squash merges use PR title as commit message (Release vX.Y.Z), not Merge pull request...
• Added ^Release v pattern to the gate check

Test plan

• Merge this PR (squash), then trigger release-prepare and verify full flow

[github-actions]

🎉 PR Validation ✅ PASSED

Commit: 85be92826765d20cbeb016f9e1c65efc9c06a838
Branch: fix/release-gate-squash

Checks:

• ✅ Release guard (no version/changelog changes)
• ✅ Dependencies installed
• ✅ Type check passed
• ✅ Linting passed
• ✅ Format check passed
• ✅ Tests + coverage passed
• ✅ Build successful

Ready to merge! ✨

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⏰ Generated at: 2026-03-29T14:27:58.665Z