test(app): add manual performance diagnostics (#32937)

packages/app/e2e/performance/playwright.config.ts

@@ -0,0 +1,20 @@
+import config from "../../playwright.config"
+
+const port = Number(process.env.PLAYWRIGHT_PORT ?? 3000)
+process.env.PLAYWRIGHT_SERVER_PORT = String(port)
+process.env.OPENCODE_PERFORMANCE_RUN_ID ??= `${new Date().toISOString().replace(/[:.]/g, "-")}-${process.pid}`
+
+export default {
+  ...config,
+  testDir: ".",
+  testIgnore: "unit/**",
+  outputDir: "../test-results/performance",
+  fullyParallel: false,
+  workers: 1,
+  reporter: [["html", { outputFolder: "../playwright-report/performance", open: "never" }], ["line"]],
+  webServer: {
+    ...config.webServer,
+    command: `bun run build && bun run serve -- --host 0.0.0.0 --port ${port} --strictPort`,
+    reuseExistingServer: false,
+  },
+}