CLI-5: Restore user input required notifications

[szmania]

Summary

This PR restores the user input required notifications that were inadvertently removed or disabled in recent changes.

Changes Made

• Restored user input required notification functionality
• Fixed notification triggering for user input prompts
• Added proper control over notification triggering in agent coder
• Implemented notification triggering based on agent reflection
• Removed unnecessary ring_bell calls to prevent duplicate notifications
• Ensured single notification for confirmations
• Refactored notification logic to separate user input notification concerns
• Added TUI mode support for user input notifications

Testing

• All existing tests continue to pass
• Notifications now properly trigger when user input is required
• No duplicate notifications observed during testing

Related Issues

Fixes CLI-5: User input notifications not appearing

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature
• Breaking change
• Documentation update