fix(tui): drain stdin on exit to avoid Kitty release leak

Drain stdin for up to 1s after disabling Kitty protocol so in-flight key
release events are consumed before the shell regains control.

Fixes #1204

packages/tui/test/virtual-terminal.ts

@@ -36,8 +36,8 @@ export class VirtualTerminal implements Terminal {
 		this.xterm.write("\x1b[?2004h");
 	}
 
-	async prepareForExit(_drainMs?: number): Promise<void> {
-		// No-op for virtual terminal - no Kitty protocol to drain
+	async drainInput(_maxMs?: number, _idleMs?: number): Promise<void> {
+		// No-op for virtual terminal - no stdin to drain
 	}
 
 	stop(): void {