fix(tui): suspend Ink properly when opening $EDITOR via Ctrl+G

The Ctrl+G handler was toggling the alt-screen by hand
(`\x1b[?1049l` ... `\x1b[?1049h`) without releasing stdin or kitty
keyboard mode, so the launched editor would lose keystrokes (Ink kept
swallowing them) and editors that don't speak CSI-u (e.g. nano) would
print "Unknown sequence" for every Ctrl-key.

Switch to `withInkSuspended` from @hermes/ink, the same helper
`/setup` already uses. It pauses Ink, removes stdin listeners, drops
raw mode, disables kitty/modifyOtherKeys + mouse + focus reporting,
runs the editor, then restores everything with a full repaint.

ui-tui/src/app/interfaces.ts

@@ -121,7 +121,7 @@ export interface ComposerActions {
   dequeue: () => string | undefined
   enqueue: (text: string) => void
   handleTextPaste: (event: PasteEvent) => MaybePromise<ComposerPasteResult | null>
-  openEditor: () => void
+  openEditor: () => Promise<void>
   pushHistory: (text: string) => void
   replaceQueue: (index: number, text: string) => void
   setCompIdx: StateSetter<number>