Add helper functions for key detection and update usage

- Add isCtrlA/C/E/K/O/P/T/U/W helper functions that check both raw and Kitty formats
- Add isAltBackspace helper function
- Refactor editor.ts, input.ts, select-list.ts to use helper functions
- Refactor custom-editor.ts, session-selector.ts, user-message-selector.ts
- Add CHANGELOG entry for the Shift+Enter fix

packages/tui/src/index.ts

@@ -19,7 +19,22 @@ export { Spacer } from "./components/spacer.js";
 export { Text } from "./components/text.js";
 export { TruncatedText } from "./components/truncated-text.js";
 // Kitty keyboard protocol helpers
-export { isCtrlC, isKittyCtrl, isKittyKey, isShiftTab, Keys } from "./keys.js";
+export {
+	isAltBackspace,
+	isCtrlA,
+	isCtrlC,
+	isCtrlE,
+	isCtrlK,
+	isCtrlO,
+	isCtrlP,
+	isCtrlT,
+	isCtrlU,
+	isCtrlW,
+	isKittyCtrl,
+	isKittyKey,
+	isShiftTab,
+	Keys,
+} from "./keys.js";
 // Terminal interface and implementations
 export { ProcessTerminal, type Terminal } from "./terminal.js";
 // Terminal image support