Add automated version management

[clouatre]

Summary

Implements automated weekly version checks and PR creation for Goose updates.

Changes

• Workflow: .github/workflows/check-version.yml

  • Runs every Monday at 9am UTC
  • Checks for new Goose releases from block/goose
  • Auto-creates PR if new version found
  • Manual trigger available via workflow_dispatch

• Dependabot: .github/dependabot.yml

  • Weekly updates for GitHub Actions dependencies
  • Auto-creates PRs for actions/checkout, actions/cache, etc.

Testing

• ✅ YAML syntax validated
• ✅ GitHub API calls tested (gh api repos/block/goose/releases/latest)
• ✅ yq commands tested (version extraction/update)
• ⏳ Workflow execution pending (will test after merge)

Notes

• README already references action.yml for default version (no manual updates needed)
• Only action.yml requires updating (simpler than setup-q-cli-action)

Related

• setup-q-cli-action: PR fix: change action name to 'Setup Goose CLI' for marketplace uniqueness #6 (merged, tested, working)
• Phase 2 automation complete for both repos