feat(driver-pwa): balance screen (hero total + accounts)

Co-Authored-By: claude-flow <ruv@ruv.net>

driver-pwa/frontend/src/pages/BalancePage.test.tsx

@@ -0,0 +1,35 @@
+import { describe, it, expect, vi } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { MemoryRouter } from "react-router-dom";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+
+vi.mock("@/api/driver", () => ({
+  getBalance: vi.fn(async () => ({
+    accounts: [
+      { bucket: "Долг аренда", balance: -3200 },
+      { bucket: "Депозит", balance: 5000 },
+    ],
+  })),
+}));
+
+import { BalancePage } from "./BalancePage";
+
+function wrap() {
+  const qc = new QueryClient();
+  return render(
+    <QueryClientProvider client={qc}>
+      <MemoryRouter><BalancePage /></MemoryRouter>
+    </QueryClientProvider>
+  );
+}
+
+describe("BalancePage", () => {
+  it("shows hero total (sum of negatives) and account rows", async () => {
+    wrap();
+    expect(await screen.findByText("Долг аренда")).toBeInTheDocument();
+    expect(screen.getByText("Депозит")).toBeInTheDocument();
+    // Appears in both the hero total and the single debt account row.
+    expect(screen.getAllByText("−3 200 ₽").length).toBeGreaterThan(0);
+    expect(screen.getByRole("button", { name: /Пополнить/i })).toBeInTheDocument();
+  });
+});