feat(coding-agent): allow hiding working loader

closes #3674

packages/coding-agent/src/core/extensions/runner.ts

@@ -193,6 +193,7 @@ const noOpUIContext: ExtensionUIContext = {
 	onTerminalInput: () => () => {},
 	setStatus: () => {},
 	setWorkingMessage: () => {},
+	setWorkingVisible: () => {},
 	setWorkingIndicator: () => {},
 	setHiddenThinkingLabel: () => {},
 	setWidget: () => {},

packages/coding-agent/src/core/extensions/types.ts

@@ -142,6 +142,9 @@ export interface ExtensionUIContext {
 	/** Set the working/loading message shown during streaming. Call with no argument to restore default. */
 	setWorkingMessage(message?: string): void;
 
+	/** Show or hide the built-in interactive working loader row during streaming. */
+	setWorkingVisible(visible: boolean): void;
+
 	/**
 	 * Configure the interactive working indicator shown during streaming.
 	 *