feat(frontend): bootstrap Vite + React 19 + TS strict toolchain (F0.1)

- Vite 8 / React 19 / TS 6 strict (noUncheckedIndexedAccess, no baseUrl deprecation)
- Tailwind 4 via @tailwindcss/vite (no PostCSS step)
- TanStack Query 5, react-router-dom 7, Recharts, clsx
- Vitest + Testing Library + jsdom for unit tests
- Playwright skeleton + first smoke spec (login redirect)
- ESLint flat config: typescript-eslint type-checked, react-hooks, react-refresh, prettier
- Prettier config (semi, single quotes, 100-col, lf)
- IBM Plex font @font-face declarations targeting /fonts/ (self-host, no CDN — OPSEC)

frontend/playwright.config.ts

@@ -0,0 +1,26 @@
+import { defineConfig, devices } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './e2e',
+  fullyParallel: true,
+  forbidOnly: !!process.env.CI,
+  retries: process.env.CI ? 2 : 0,
+  workers: process.env.CI ? 1 : undefined,
+  reporter: 'html',
+  use: {
+    baseURL: 'http://localhost:5173',
+    trace: 'on-first-retry',
+  },
+  projects: [
+    {
+      name: 'chromium',
+      use: { ...devices['Desktop Chrome'] },
+    },
+  ],
+  webServer: {
+    command: 'npm run dev',
+    url: 'http://localhost:5173',
+    reuseExistingServer: !process.env.CI,
+    timeout: 60_000,
+  },
+});