refactor: remove interactive help system

Remove interactive help feature that showed an interactive menu when running
'socket --help'. Now 'socket --help' always shows the classic help text
immediately without prompts.

Removed:
- packages/cli/src/utils/cli/interactive-help.mts (entire file)
- Interactive help logic from with-subcommands.mts
- Help category support (--help=category syntax)
- Unused isInteractive import

This simplifies the help system and makes --help behavior more predictable
and consistent with standard CLI conventions.

Author: jdalton