feat(cli): Add named design mutations

[Xuepoo]

Summary

• add nine revision-protected intention-level design commands
• add dry-run generated-ID replay and stable JSON envelopes
• protect local documents with verified file reads, sidecar locks, and atomic create/replace transactions
• add Changesets and tag-triggered npm publishing

Verification

• bun run verify
• 18 tests cover parsing, all commands, revisions, locks, file kinds, faults, and dry-run replay
• npm package dry-run includes the Bun executable and runtime sources

Documentation

• README, CHANGELOG, and Changeset are current.