Improve openwebui detection and confirmation prompts

[BillJr99]

Summary

This PR enhances the install tool script to better handle OpenWebUI detection and improves the user experience for confirmation prompts.

Key Changes

• Enhanced _it_confirm() function:

  • Now displays context-aware hints (e.g., "Y/n" vs "y/N") based on the default value
  • Refactored to use direct TTY I/O operations (_it_open_tty, file descriptors 3 and 4) instead of delegating to _it_read()
  • Properly handles case-insensitive default values

• Added OpenWebUI endpoint configuration:

  • When OpenWebUI is not reachable at the default URL, the script now prompts users to provide a custom endpoint (useful for Docker deployments on non-standard ports)
  • Stores the custom endpoint in CLK_OPENWEBUI_ENDPOINT environment variable
  • Optionally prompts for API key configuration via CLK_OPENWEBUI_API_KEY for authenticated instances
  • Re-checks tool availability after configuration before proceeding with installation
  • Provides clear feedback if the service remains unreachable after configuration

Implementation Details

• The confirmation prompt now uses a case statement to determine the appropriate hint text based on the default value
• OpenWebUI configuration is only triggered when the tool name is "openwebui" and initial detection fails
• Configuration values are persisted to the environment file for future use
• The flow gracefully handles both successful re-detection and continued unavailability scenarios

https://claude.ai/code/session_01HbzTVqzDcadZrQhRQM2mrF