huskies: merge 1120 story Silence intentional-error stderr in frontend tests so failures stand out

frontend/src/App.test.tsx

@@ -160,6 +160,7 @@ describe("App", () => {
 	});
 
 	it("shows error when openProject fails", async () => {
+		const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
 		mockedApi.openProject.mockRejectedValue(new Error("Path does not exist"));
 
 		await renderApp();
@@ -182,6 +183,7 @@ describe("App", () => {
 		await waitFor(() => {
 			expect(screen.getByText(/Path does not exist/)).toBeInTheDocument();
 		});
+		errorSpy.mockRestore();
 	});
 
 	it("shows known projects list", async () => {

frontend/src/api/agents.test.ts

@@ -266,6 +266,8 @@ describe("subscribeAgentStream", () => {
 	});
 
 	it("handles malformed JSON without throwing", () => {
+		vi.spyOn(console, "error").mockImplementation(() => {});
+
 		subscribeAgentStream("42_story_test", "coder", vi.fn());
 
 		expect(() => {

frontend/src/components/Chat.commands.test.tsx

@@ -472,9 +472,16 @@ describe("Slash command handling (Story 374)", () => {
 });
 
 describe("Story 1058: WebSocket errors do not appear in chat", () => {
+	let consoleSpy: ReturnType<typeof vi.spyOn>;
+
 	beforeEach(() => {
 		capturedWsHandlers = null;
 		setupMocks();
+		consoleSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+	});
+
+	afterEach(() => {
+		consoleSpy.mockRestore();
 	});
 
 	it("does not add a chat message when onError is called", async () => {

frontend/src/components/selection/usePathCompletion.test.ts

@@ -227,6 +227,7 @@ describe("usePathCompletion hook", () => {
 	});
 
 	it("sets completionError when listDirectoryAbsolute throws an Error", async () => {
+		const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
 		mockListDir.mockRejectedValue(new Error("Permission denied"));
 
 		const { result } = renderHook(() =>
@@ -242,9 +243,13 @@ describe("usePathCompletion hook", () => {
 		await waitFor(() => {
 			expect(result.current.completionError).toBe("Permission denied");
 		});
+
+		expect(errorSpy).toHaveBeenCalledWith(new Error("Permission denied"));
+		errorSpy.mockRestore();
 	});
 
 	it("sets generic completionError when listDirectoryAbsolute throws a non-Error", async () => {
+		const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
 		mockListDir.mockRejectedValue("some string error");
 
 		const { result } = renderHook(() =>
@@ -262,6 +267,9 @@ describe("usePathCompletion hook", () => {
 				"Failed to compute suggestion.",
 			);
 		});
+
+		expect(errorSpy).toHaveBeenCalledWith("some string error");
+		errorSpy.mockRestore();
 	});
 
 	it("clears suggestionTail when selected match path does not start with input", async () => {