Replace automatic version reading from VERSION file with interactive prompts for version (major.minor.build) and ISO variant name (e.g., cli, gnome, kde).
Changes:
- Remove automatic VERSION file reading; now serves as default with prompt
- Add interactive prompts for version and variant name with validation
- Simplify ISO naming from FWS-v{major}-{minor}-{build}-{date}-x86_64.iso to fws-{version}-{variant}.iso
- Update hostname from 'archiso' to 'fws'
- Add custom FWS logo for fastfetch with color configuration
- Improve error messages and user feedback
This enables flexible build variants and streamlines the build process.
