fix(site): hide hidden apps in Tasks tabs (#24823)

## Summary
- Exclude `hidden` workspace apps from the Tasks page app tabs.
- Keep terminal link agent selection based on the full app list so
hidden apps do not affect terminal routing.
- Add a focused unit test covering hidden app filtering in `TaskApps`.

## Test plan
- `pnpm --dir site test TaskApps.test.tsx`
- `pnpm -C site exec biome check src/pages/TaskPage/TaskApps.tsx
src/pages/TaskPage/TaskApps.test.tsx`


Made with [Cursor](https://cursor.com)

site/src/pages/TaskPage/TaskApps.stories.tsx

@@ -65,6 +65,19 @@ export const WithMixedApps: Story = {
 	},
 };
 
+export const WithHiddenApps: Story = {
+	args: {
+		task: mockTask,
+		workspace: mockWorkspaceWithApps([
+			mockEmbeddedApp("Visible App"),
+			{
+				...mockEmbeddedApp("Hidden App"),
+				hidden: true,
+			},
+		]),
+	},
+};
+
 export const WithWildcardWarning: Story = {
 	decorators: [
 		withAuthProvider,

site/src/pages/TaskPage/TaskApps.tsx

@@ -31,16 +31,17 @@ type TaskAppsProps = {
 const TERMINAL_TAB_ID = "terminal";
 
 export const TaskApps: FC<TaskAppsProps> = ({ task, workspace }) => {
-	const apps = getAllAppsWithAgent(workspace).filter(
+	const allApps = getAllAppsWithAgent(workspace);
+	const apps = allApps.filter(
 		// The Chat UI app will be displayed in the sidebar, so we don't want to
 		// show it as a web app.
-		(app) => app.id !== task.workspace_app_id,
+		(app) => app.id !== task.workspace_app_id && !app.hidden,
 	);
 	const [embeddedApps, externalApps] = splitEmbeddedAndExternalApps(apps);
 	const [activeAppId, setActiveAppId] = useState(embeddedApps.at(0)?.id);
 	const hasAvailableAppsToDisplay =
 		embeddedApps.length > 0 || externalApps.length > 0;
-	const taskAgent = apps.at(0)?.agent;
+	const taskAgent = allApps.at(0)?.agent;
 	const terminalHref = getTerminalHref({
 		username: task.owner_name,
 		workspace: task.workspace_name,