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/coding-agent/src/modes/interactive/components/custom-editor.ts

@@ -1,4 +1,4 @@
-import { Editor, isCtrlC, isCtrlO, isCtrlP, isCtrlT, isShiftTab } from "@mariozechner/pi-tui";
+import { Editor, isCtrlC, isCtrlD, isCtrlO, isCtrlP, isCtrlT, isShiftTab } from "@mariozechner/pi-tui";
 
 /**
  * Custom editor that handles Escape and Ctrl+C keys for coding-agent
@@ -6,6 +6,7 @@ import { Editor, isCtrlC, isCtrlO, isCtrlP, isCtrlT, isShiftTab } from "@marioze
 export class CustomEditor extends Editor {
 	public onEscape?: () => void;
 	public onCtrlC?: () => void;
+	public onCtrlD?: () => void;
 	public onShiftTab?: () => void;
 	public onCtrlP?: () => void;
 	public onCtrlO?: () => void;
@@ -49,6 +50,15 @@ export class CustomEditor extends Editor {
 			return;
 		}
 
+		// Intercept Ctrl+D (only when editor is empty)
+		if (isCtrlD(data)) {
+			if (this.getText().length === 0 && this.onCtrlD) {
+				this.onCtrlD();
+			}
+			// Always consume Ctrl+D (don't pass to parent)
+			return;
+		}
+
 		// Pass to parent for normal handling
 		super.handleInput(data);
 	}

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -562,6 +562,7 @@ export class InteractiveMode {
 		};
 
 		this.editor.onCtrlC = () => this.handleCtrlC();
+		this.editor.onCtrlD = () => this.handleCtrlD();
 		this.editor.onShiftTab = () => this.cycleThinkingLevel();
 		this.editor.onCtrlP = () => this.cycleModel();
 		this.editor.onCtrlO = () => this.toggleToolOutputExpansion();
@@ -1128,6 +1129,12 @@ export class InteractiveMode {
 		}
 	}
 
+	private handleCtrlD(): void {
+		// Only called when editor is empty (enforced by CustomEditor)
+		this.stop();
+		process.exit(0);
+	}
+
 	private updateEditorBorderColor(): void {
 		if (this.isBashMode) {
 			this.editor.borderColor = theme.getBashModeBorderColor();