ratatui-patterns

# Ratatui Patterns Modern-ratatui knowledge pack. Current stable: **ratatui 0.30.2** (2026-06). Model training data predates 0.29. The biggest failure mode is reimplementing by hand what the library now provides; the second is asserting API shapes from memory. Both have the same fix: **work from the bundled references, not from memory.** ## Hard Rules 1. Before writing any TUI render/layout/lifecycle code, read `references/modernization-checklist.md`. If the thing being built appears in it, use the built-in. 2. Before claiming an API exists or writing a signature, verify it in `references/api-reference.md` (generated from ratatui source, grep-friendly). If it is not there and not in `references/limitations.md`, pull live docs (below) before hand-rolling. 3. Custom render code is allowed only for needs listed in `references/limitations.md` (the verified beyond-API catalog). Anything else custom is a defect. 4. Render logic ships with `TestBackend` tests per `references/testing.md`. 5. Depend only on the `ratatui` umbrella crate, never on `ratatui-core`/`-widgets` directly. If `default-features = false`, re-add `layout-cache`. 6. Mouse events are opt-in. `ratatui::init()`/`run()` do not enable mouse capture; that needs `EnableMouseCapture`/`DisableMouseCapture` around the loop (`references/api-reference.md` §14). 7. The event loop can go async (`crossterm`'s `event-stream` feature + `EventStream` for `tokio::select!`); `Terminal::draw` stays sync rega...