Add Ctrl+D to exit when editor is empty

- Add isCtrlD helper to keys.ts
- CustomEditor intercepts Ctrl+D and only triggers callback when editor is empty
- Single Ctrl+D with empty input exits immediately
- Update CHANGELOG to frame as feature (Kitty protocol support) not fix

packages/tui/src/index.ts

@@ -23,6 +23,7 @@ export {
 	isAltBackspace,
 	isCtrlA,
 	isCtrlC,
+	isCtrlD,
 	isCtrlE,
 	isCtrlK,
 	isCtrlO,

packages/tui/src/keys.ts

@@ -18,6 +18,7 @@ const CODEPOINTS = {
 	// Letters (lowercase ASCII)
 	a: 97,
 	c: 99,
+	d: 100,
 	e: 101,
 	k: 107,
 	o: 111,
@@ -52,6 +53,7 @@ export const Keys = {
 	// Ctrl+<letter> combinations
 	CTRL_A: kittySequence(CODEPOINTS.a, MODIFIERS.ctrl),
 	CTRL_C: kittySequence(CODEPOINTS.c, MODIFIERS.ctrl),
+	CTRL_D: kittySequence(CODEPOINTS.d, MODIFIERS.ctrl),
 	CTRL_E: kittySequence(CODEPOINTS.e, MODIFIERS.ctrl),
 	CTRL_K: kittySequence(CODEPOINTS.k, MODIFIERS.ctrl),
 	CTRL_O: kittySequence(CODEPOINTS.o, MODIFIERS.ctrl),
@@ -97,6 +99,7 @@ export function isKittyKey(data: string, codepoint: number, modifier: number): b
 const RAW = {
 	CTRL_A: "\x01",
 	CTRL_C: "\x03",
+	CTRL_D: "\x04",
 	CTRL_E: "\x05",
 	CTRL_K: "\x0b",
 	CTRL_O: "\x0f",
@@ -122,6 +125,13 @@ export function isCtrlC(data: string): boolean {
 	return data === RAW.CTRL_C || data === Keys.CTRL_C;
 }
 
+/**
+ * Check if input matches Ctrl+D (raw byte or Kitty protocol).
+ */
+export function isCtrlD(data: string): boolean {
+	return data === RAW.CTRL_D || data === Keys.CTRL_D;
+}
+
 /**
  * Check if input matches Ctrl+E (raw byte or Kitty protocol).
  */