test(web-tanstack): add Playwright scaffold + skipped home spec

apps/web-tanstack/playwright.config.ts

@@ -0,0 +1,21 @@
+import { defineConfig, devices } from "@playwright/test";
+
+export default defineConfig({
+  testDir: "./e2e",
+  fullyParallel: true,
+  retries: process.env.CI ? 2 : 0,
+  reporter: "list",
+  use: {
+    baseURL: "http://localhost:3000",
+    trace: "on-first-retry",
+  },
+  projects: [
+    {
+      name: "chromium",
+      use: { ...devices["Desktop Chrome"] },
+    },
+  ],
+  // No webServer: web-tanstack tests run against the shared web-next backend
+  // (port 3000). When TanStack Start runtime is wired in a future plan, add
+  // a webServer block here pointing at port 3002.
+});