Release 5.1.0

fix: Node 24 compatibility (#213)

- Upgrade inquirer from ^6.2.2 to ^8.2.6
- Remove monaca-inquirer dependency (deprecated, last updated 2016)
- Unify create.js to use standard inquirer for all platforms
- Add "Back to categories" navigation option in template selection
- Add engines field requiring Node >=18.0.0
- Bump version to 5.1.0

BREAKING CHANGES:
- Minimum Node version is now 18.0.0
- Template preview with "P" key removed (was non-Windows only)

Fixes #212