feat(hooks): expose setTitle to HookUIContext (#446)

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

@@ -685,6 +685,7 @@ export class InteractiveMode {
 			notify: (message, type) => this.showHookNotify(message, type),
 			setStatus: (key, text) => this.setHookStatus(key, text),
 			setWidget: (key, content) => this.setHookWidget(key, content),
+			setTitle: (title) => this.ui.terminal.setTitle(title),
 			custom: (factory) => this.showHookCustom(factory),
 			setEditorText: (text) => this.editor.setText(text),
 			getEditorText: () => this.editor.getText(),

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

@@ -145,6 +145,16 @@ export async function runRpcMode(session: AgentSession): Promise<never> {
 			// Component factories are not supported in RPC mode - would need TUI access
 		},
 
+		setTitle(title: string): void {
+			// Fire and forget - host can implement terminal title control
+			output({
+				type: "hook_ui_request",
+				id: crypto.randomUUID(),
+				method: "setTitle",
+				title,
+			} as RpcHookUIRequest);
+		},
+
 		async custom() {
 			// Custom UI not supported in RPC mode
 			return undefined as never;

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

@@ -196,6 +196,7 @@ export type RpcHookUIRequest =
 			widgetKey: string;
 			widgetLines: string[] | undefined;
 	  }
+	| { type: "hook_ui_request"; id: string; method: "setTitle"; title: string }
 	| { type: "hook_ui_request"; id: string; method: "set_editor_text"; text: string };
 
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