Ink's `useApp()` returns `{ exit, waitUntilRenderFlush }`. vue-tui previously
exposed only `exit()` via `useExit()` and kept `waitUntilRenderFlush` on the
`TuiApp` handle alone. Align the public surface with Ink: add `useAppContext()`
returning the same pair, and remove `useExit()`.
- thread `waitUntilRenderFlush` into the injected `AppContext` via a hoisted
impl shared by the `TuiApp` handle and the composable, so both resolve
identically
- add `useAppContext()`; delete `useExit()`; migrate all call sites, PTY
fixtures, examples, READMEs and the public-API surface test
- port Ink's two "useApp waitUntilRenderFlush" tests; Ink's third relies on
React concurrent mode (N/A in Vue)
- rewrite the ink-divergences entry: this is now a *naming* divergence
(`useAppContext` vs `useApp`, mirroring `createApp` vs `render`), not a
surface one — and fix the prior wrong claim that Ink's `useApp` returns
stdin/stdout/stderr
The name is qualified (`useAppContext`, not `useApp`) so it doesn't read as the
Vue application instance (`createApp`/`app.mount`) — the same Vue-native naming
choice vue-tui already makes with `createApp()` vs Ink's `render()`.
BREAKING CHANGE: `useExit()` is removed. Replace `const exit = useExit()` with
`const { exit } = useAppContext()`.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Yunfei He
9d1e4d7805