Build terminal user interfaces (TUIs) in Rust with Ratatui (v0.30). Use this skill whenever working with the ratatui crate for creating interactive terminal applications, including: (1) Setting up a new Ratatui project, (2) Creating or modifying terminal UI layouts, (3) Implementing widgets (lists, tables, charts, text, gauges, etc.), (4) Handling keyboard/mouse input and events, (5) Structuring TUI application architecture (TEA, component-based, or monolithic patterns), (6) Writing custom widgets, (7) Managing application state in a TUI context, (8) Terminal setup/teardown and panic handling, (9) Testing TUI rendering with TestBackend. Also triggers for questions about crossterm event handling in a Ratatui context, tui-input, tui-textarea, or any ratatui-* ecosystem crate.