feat(WOR-TSK-196): implement bump integration tests and fix unified prerelease resolution

[miguelramos]

• Add comprehensive Node.js integration tests for bump commands (Story 5.6)

  • bumpPreview: preview, showDiff, filters, no changes to files
  • bumpApply: version bumps, git commit/tag, prerelease (alpha/beta/rc/canary)
  • bumpSnapshot: custom formats, variables, changesets not archived
  • Error handling and type verification tests
  • Prerelease and snapshot workflow tests

• Fix unified strategy bug in resolve_unified_with_prerelease_auto

  • Was only updating changeset packages instead of ALL workspace packages
  • Now correctly applies unified version to all packages with proper UpdateReason

• Simplify prerelease API (breaking change in CLI/NAPI)

  • User now passes simple tag: --prerelease beta (not beta.create)
  • Mode (create/increment/promote) is automatically inferred:
    • Stable -> Prerelease: 1.2.3 + beta -> 1.3.0-beta.0
    • Same tag increment: 1.3.0-beta.0 + beta -> 1.3.0-beta.1
    • Different tag: 1.3.0-alpha.2 + beta -> 1.3.0-beta.0
    • Promote: omit --prerelease -> 1.3.0

• Update prerelease validation to reject dots and special chars

• Update CLI and README documentation for new prerelease format

• Regenerate NAPI bindings (v2.0.15)

BREAKING CHANGE: Prerelease format changed from 'tag.mode' to simple 'tag'