chore(release): release v2.31.3

[EyJunge1]

Summary

• Bump package version from 2.31.2 → 2.31.3
• Ships the SkillsManager stale Turso handle fix from #413 / #412
• Also includes the JSONC trailing-comma fix from #411

Test plan

• CI quality checks pass on this PR
• After merge: tag v2.31.3 on main and push the tag to trigger .github/workflows/release.yml
• Confirm npm publish + GitHub Release notes for v2.31.3

Checklist

• Branch is based on main (do not open PRs from commits already on main)
• bun test passes (or N/A)
• bun run typecheck passes (or N/A)
• bun run check passes (format + lint + typecheck; or N/A)
• Docs / README updated when behavior or contribution process changes (N/A)