feat(FN-4760): complete Step 4 — add PR checks list UI

Fusion-Task-Id: FN-4760
Fusion-Task-Lineage: 71db4a53-ee59-49f0-a1f7-232954b86660

packages/dashboard/app/components/__tests__/PrChecksList.test.tsx

@@ -0,0 +1,58 @@
+import { describe, it, expect, vi } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import { PrChecksList } from "../PrChecksList";
+
+describe("PrChecksList", () => {
+  it("orders failing checks first", () => {
+    render(
+      <PrChecksList
+        checks={[
+          { name: "pass", required: true, state: "success" },
+          { name: "pending", required: true, state: "pending" },
+          { name: "fail", required: true, state: "failure" },
+        ]}
+        rollup="failure"
+        loading={false}
+        onRefresh={() => {}}
+      />,
+    );
+
+    const items = screen.getAllByRole("listitem");
+    expect(items[0]).toHaveTextContent("fail");
+  });
+
+  it("renders summary and details links", () => {
+    render(
+      <PrChecksList
+        checks={[{ name: "fail", required: true, state: "failure", detailsUrl: "https://example.com/details" }]}
+        rollup="failure"
+        loading={false}
+        onRefresh={() => {}}
+      />,
+    );
+
+    expect(screen.getByText("0 passing, 1 failing, 0 pending")).toBeInTheDocument();
+    expect(screen.getByRole("link", { name: /View details/i })).toHaveAttribute("href", "https://example.com/details");
+  });
+
+  it("shows empty state", () => {
+    render(<PrChecksList checks={[]} rollup="unknown" loading={false} onRefresh={() => {}} />);
+    expect(screen.getByText("No checks reported yet")).toBeInTheDocument();
+  });
+
+  it("shows error state and retry", () => {
+    const onRefresh = vi.fn();
+    render(<PrChecksList checks={[]} rollup="unknown" loading={false} error="nope" onRefresh={onRefresh} />);
+
+    fireEvent.click(screen.getByRole("button", { name: /Retry/i }));
+    expect(onRefresh).toHaveBeenCalledTimes(1);
+  });
+
+  it("refresh button triggers onRefresh", () => {
+    const onRefresh = vi.fn();
+    render(<PrChecksList checks={[]} rollup="unknown" loading={false} onRefresh={onRefresh} />);
+
+    fireEvent.click(screen.getByRole("button", { name: "Refresh checks" }));
+    expect(onRefresh).toHaveBeenCalledTimes(1);
+  });
+});