feat(hooks): add setWidget API for multi-line status displays

- ctx.ui.setWidget(key, lines) for multi-line displays above editor
- Widgets appear below 'Working...' indicator, above editor
- Supports ANSI styling including strikethrough
- Added theme.strikethrough() method
- Plan-mode hook now shows todo list with checkboxes
- Completed items show checked box and strikethrough text

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

@@ -141,6 +141,10 @@ export class InteractiveMode {
 	private hookInput: HookInputComponent | undefined = undefined;
 	private hookEditor: HookEditorComponent | undefined = undefined;
 
+	// Hook widgets (multi-line status displays)
+	private hookWidgets = new Map<string, string[]>();
+	private widgetContainer!: Container;
+
 	// Custom tools for custom rendering
 	private customTools: Map<string, LoadedCustomTool>;
 
@@ -171,6 +175,7 @@ export class InteractiveMode {
 		this.chatContainer = new Container();
 		this.pendingMessagesContainer = new Container();
 		this.statusContainer = new Container();
+		this.widgetContainer = new Container();
 		this.keybindings = KeybindingsManager.create();
 		this.editor = new CustomEditor(getEditorTheme(), this.keybindings);
 		this.editorContainer = new Container();
@@ -326,6 +331,7 @@ export class InteractiveMode {
 		this.ui.addChild(this.chatContainer);
 		this.ui.addChild(this.pendingMessagesContainer);
 		this.ui.addChild(this.statusContainer);
+		this.ui.addChild(this.widgetContainer);
 		this.ui.addChild(new Spacer(1));
 		this.ui.addChild(this.editorContainer);
 		this.ui.addChild(this.footer);
@@ -614,6 +620,40 @@ export class InteractiveMode {
 		this.ui.requestRender();
 	}
 
+	/**
+	 * Set a hook widget (multi-line status display).
+	 */
+	private setHookWidget(key: string, lines: string[] | undefined): void {
+		if (lines === undefined) {
+			this.hookWidgets.delete(key);
+		} else {
+			this.hookWidgets.set(key, lines);
+		}
+		this.renderWidgets();
+	}
+
+	/**
+	 * Render all hook widgets to the widget container.
+	 */
+	private renderWidgets(): void {
+		if (!this.widgetContainer) return;
+		this.widgetContainer.clear();
+
+		if (this.hookWidgets.size === 0) {
+			this.ui.requestRender();
+			return;
+		}
+
+		// Render each widget
+		for (const [_key, lines] of this.hookWidgets) {
+			for (const line of lines) {
+				this.widgetContainer.addChild(new Text(line, 1, 0));
+			}
+		}
+
+		this.ui.requestRender();
+	}
+
 	/**
 	 * Create the HookUIContext for hooks and tools.
 	 */
@@ -624,6 +664,7 @@ export class InteractiveMode {
 			input: (title, placeholder) => this.showHookInput(title, placeholder),
 			notify: (message, type) => this.showHookNotify(message, type),
 			setStatus: (key, text) => this.setHookStatus(key, text),
+			setWidget: (key, lines) => this.setHookWidget(key, lines),
 			custom: (factory) => this.showHookCustom(factory),
 			setEditorText: (text) => this.editor.setText(text),
 			getEditorText: () => this.editor.getText(),

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

@@ -376,6 +376,10 @@ export class Theme {
 		return chalk.inverse(text);
 	}
 
+	strikethrough(text: string): string {
+		return chalk.strikethrough(text);
+	}
+
 	getFgAnsi(color: ThemeColor): string {
 		const ansi = this.fgColors.get(color);
 		if (!ansi) throw new Error(`Unknown theme color: ${color}`);

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

@@ -131,6 +131,17 @@ export async function runRpcMode(session: AgentSession): Promise<never> {
 			} as RpcHookUIRequest);
 		},
 
+		setWidget(key: string, lines: string[] | undefined): void {
+			// Fire and forget - host can implement widget display
+			output({
+				type: "hook_ui_request",
+				id: crypto.randomUUID(),
+				method: "setWidget",
+				widgetKey: key,
+				widgetLines: lines,
+			} as RpcHookUIRequest);
+		},
+
 		async custom() {
 			// Custom UI not supported in RPC mode
 			return undefined as never;

packages/coding-agent/src/modes/rpc/rpc-types.ts

@@ -189,6 +189,13 @@ export type RpcHookUIRequest =
 			notifyType?: "info" | "warning" | "error";
 	  }
 	| { type: "hook_ui_request"; id: string; method: "setStatus"; statusKey: string; statusText: string | undefined }
+	| {
+			type: "hook_ui_request";
+			id: string;
+			method: "setWidget";
+			widgetKey: string;
+			widgetLines: string[] | undefined;
+	  }
 	| { type: "hook_ui_request"; id: string; method: "set_editor_text"; text: string };
 
 // ============================================================================