Feature Request: TUI Testing Support for Fossil Test

[dreamer-coding]

Is your feature request related to a problem? Please describe.
Fossil Test currently lacks built-in support for testing Text User Interfaces (TUIs). This makes it challenging to validate interactive CLI applications built with TUIs, as existing tests focus on non-interactive input/output validation. I’m frustrated when I have to rely on external tools or write complex test scripts to simulate TUI interactions.

Describe the solution you’d like
I would like Fossil Test to include native support for TUI testing, allowing developers to:
• Simulate user input for key presses, mouse clicks, and other interactive elements.
• Validate screen output, such as layout changes, text rendering, and cursor position.
• Capture snapshots of TUI states for comparison during regression testing.
• Provide hooks for testing edge cases like resizing, input overflow, and rapid inputs.
• Offer a mock terminal environment for automated TUI tests without requiring a real terminal.

Describe alternatives you’ve considered
• Using third-party tools like expect or terminal emulators, but these add external dependencies and are difficult to integrate seamlessly into Fossil Test.
• Writing custom scripts for each TUI component, but this approach is time-intensive and prone to errors.

Additional context
This feature would greatly benefit developers creating interactive CLI applications, providing them with a streamlined way to ensure TUI reliability. It could also help catch issues that only manifest in interactive environments, improving overall application quality.