fix: refine notification bell count (#2180)

Co-authored-by: Vaibhaav <user@example.com>

frontend/src/renderer/components/NotificationCenter.test.tsx

@@ -0,0 +1,71 @@
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import { NotificationCenter } from "./NotificationCenter";
+import type { NotificationDTO } from "../lib/notifications";
+
+const notifications: NotificationDTO[] = [
+	{
+		id: "ntf_1",
+		sessionId: "sess-1",
+		projectId: "proj-1",
+		prUrl: "",
+		type: "needs_input",
+		title: "Needs input",
+		body: "",
+		status: "unread",
+		createdAt: "2026-06-16T10:00:00Z",
+		target: { kind: "session", sessionId: "sess-1" },
+	},
+	{
+		id: "ntf_2",
+		sessionId: "sess-2",
+		projectId: "proj-1",
+		prUrl: "",
+		type: "ready_to_merge",
+		title: "Ready to merge",
+		body: "",
+		status: "unread",
+		createdAt: "2026-06-16T11:00:00Z",
+		target: { kind: "session", sessionId: "sess-2" },
+	},
+];
+
+vi.mock("@tanstack/react-router", () => ({ useNavigate: () => vi.fn() }));
+
+vi.mock("../hooks/useNotificationsQuery", () => ({
+	useMarkAllNotificationsReadMutation: () => ({ isPending: false, mutateAsync: vi.fn() }),
+	useMarkNotificationReadMutation: () => ({ isPending: false, mutateAsync: vi.fn() }),
+	useNotificationsQuery: () => ({ data: notifications, isError: false }),
+}));
+
+vi.mock("../lib/notifications", async (importOriginal) => ({
+	...((await importOriginal()) as object),
+	createNotificationsTransport: () => ({ connect: () => undefined }),
+}));
+
+function renderNotificationCenter() {
+	const queryClient = new QueryClient({ defaultOptions: { queries: { retry: false } } });
+	return render(
+		<QueryClientProvider client={queryClient}>
+			<NotificationCenter />
+		</QueryClientProvider>,
+	);
+}
+
+describe("NotificationCenter", () => {
+	it("renders a filled bell with a text-only yellow unread count", () => {
+		renderNotificationCenter();
+
+		const trigger = screen.getByRole("button", { name: "2 unread notifications" });
+		const bell = trigger.querySelector("svg");
+		const count = screen.getByText("2");
+
+		expect(bell).toHaveClass("fill-current");
+		expect(count).toHaveClass("text-[11px]");
+		expect(count).toHaveClass("text-warning");
+		expect(count).not.toHaveClass("bg-warning");
+		expect(count).not.toHaveClass("rounded-full");
+		expect(count).not.toHaveClass("text-background");
+	});
+});

frontend/src/renderer/components/NotificationCenter.tsx

@@ -91,9 +91,9 @@ export function NotificationCenter({ style }: NotificationCenterProps) {
 					style={style}
 					type="button"
 				>
-					<Bell className="h-[15px] w-[15px]" aria-hidden="true" />
+					<Bell className="h-[15px] w-[15px] fill-current" aria-hidden="true" />
 					{unreadCount > 0 ? (
-						<span className="absolute right-[5px] top-[5px] grid min-w-[15px] place-items-center rounded-full bg-warning px-1 text-[9px] font-semibold leading-[15px] text-background">
+						<span className="pointer-events-none absolute right-[3px] top-[2px] font-mono text-[11px] font-semibold leading-none text-warning">
 							{unreadCount > 99 ? "99+" : unreadCount}
 						</span>
 					) : null}