fix(installer): restore automator install compatibility

[dickymoore]

Summary

Restore BMad Automator install/update compatibility in the BMAD installer.

Problem

Current installer behavior has two linked problems:

1. legacy installs can still have Automator recorded as baut, while the bundled BMAD module registry currently advertises automator
2. the bundled Automator registry entry points at skills/module.yaml, but bmad-automator is a pure-skill payload repo and does not ship that module definition path

That combination makes quick-update / reinstall runs treat an installed Automator as having no source, producing:

• Skipping 1 module(s) - no source available: baut

and then removing the existing Automator install as if it were deselected.

Scope

This PR is intentionally limited to the installer compatibility path for that failure:

• restore the bundled Automator module code to baut for compatibility with existing installs
• treat automator and bmad-automator as CLI aliases for baut
• force --yes existing-install runs onto the full update path when explicit module/channel/tool flags are present, so commands like --modules automator --next automator are not silently downgraded to quick-update
• add source-root support to external official module resolution
• point the bundled Automator registry entry at payload/.claude/skills
• copy the Automator Python runtime (source/scripts, source/src) into the installed bmad-story-automator skill during install

Out of Scope

• broader external-module/source-root redesign
• marketplace registry changes
• unrelated Automator runtime behavior

Validation

• node test/test-installation-components.js
• commit hook also ran the full BMAD test stack successfully:
  • npm run test:refs
  • npm run test:install
  • npm run test:urls
  • npm run test:channels
  • npm run lint
  • npm run lint:md
  • npm run format:check

[dickymoore]

Superseded by #2391. This narrower draft only fixes the stale installed-module update failure ( retained in existing manifests) and leaves broader Automator installability work out of scope.