fix(coding-agent): sync extension theme changes to session settings (#1483)

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

@@ -1427,6 +1427,9 @@ export class InteractiveMode {
 				}
 				const result = setTheme(themeOrName, true);
 				if (result.success) {
+					if (this.settingsManager.getTheme() !== themeOrName) {
+						this.settingsManager.setTheme(themeOrName);
+					}
 					this.ui.requestRender();
 				}
 				return result;

packages/coding-agent/test/interactive-mode-status.test.ts

@@ -60,6 +60,54 @@ describe("InteractiveMode.showStatus", () => {
 	});
 });
 
+describe("InteractiveMode.createExtensionUIContext setTheme", () => {
+	test("persists theme changes to settings manager", () => {
+		initTheme("dark");
+
+		let currentTheme = "dark";
+		const settingsManager = {
+			getTheme: vi.fn(() => currentTheme),
+			setTheme: vi.fn((theme: string) => {
+				currentTheme = theme;
+			}),
+		};
+		const fakeThis: any = {
+			session: { settingsManager },
+			settingsManager,
+			ui: { requestRender: vi.fn() },
+		};
+
+		const uiContext = (InteractiveMode as any).prototype.createExtensionUIContext.call(fakeThis);
+		const result = uiContext.setTheme("light");
+
+		expect(result.success).toBe(true);
+		expect(settingsManager.setTheme).toHaveBeenCalledWith("light");
+		expect(currentTheme).toBe("light");
+		expect(fakeThis.ui.requestRender).toHaveBeenCalledTimes(1);
+	});
+
+	test("does not persist invalid theme names", () => {
+		initTheme("dark");
+
+		const settingsManager = {
+			getTheme: vi.fn(() => "dark"),
+			setTheme: vi.fn(),
+		};
+		const fakeThis: any = {
+			session: { settingsManager },
+			settingsManager,
+			ui: { requestRender: vi.fn() },
+		};
+
+		const uiContext = (InteractiveMode as any).prototype.createExtensionUIContext.call(fakeThis);
+		const result = uiContext.setTheme("__missing_theme__");
+
+		expect(result.success).toBe(false);
+		expect(settingsManager.setTheme).not.toHaveBeenCalled();
+		expect(fakeThis.ui.requestRender).not.toHaveBeenCalled();
+	});
+});
+
 describe("InteractiveMode.showLoadedResources", () => {
 	beforeAll(() => {
 		initTheme("dark");