Improve OpenWebUI health checks and confirmation prompts

[BillJr99]

Summary

This PR enhances the reliability of OpenWebUI endpoint detection and improves the user experience of confirmation prompts by making them more explicit about expected input.

Key Changes

OpenWebUI Health Check Improvements (scripts/install_tool.sh)

• Added HTTP-based probing as the primary method for checking OpenWebUI availability, which is more reliable than TCP port checks in minimal shell environments
• Implements curl-based health checks with a 4-second timeout, checking both the root endpoint and the /health endpoint
• Handles authenticated instances gracefully by accepting any HTTP response (including 401/403 status codes) as a sign of reachability
• Falls back to raw TCP probing for environments without curl
• Fixed port detection logic to properly default to HTTPS port 443 when the endpoint uses https:// scheme, instead of always defaulting to 8080

Confirmation Prompt Enhancement (kickoff.sh)

• Refactored _sv_confirm() to display clearer visual hints about expected input (e.g., "Y/n" vs "y/N")
• The hint now reflects the default value, making it immediately obvious to users what will happen if they just press Enter
• Improved input handling by directly reading from the input stream with proper IFS handling

Implementation Details

• The HTTP probe approach is preferred because it verifies that OpenWebUI is actually responding to requests, not just that a port is open
• The health check gracefully degrades to TCP probing when curl is unavailable, maintaining backward compatibility
• Confirmation prompts now use case-insensitive matching while providing case-sensitive visual feedback about defaults

https://claude.ai/code/session_01QSLjGr6qdeBEaFefyeipEk