test: base playwrignt setup for firefox and chrome

playwright.config.ts

@@ -1,10 +1,54 @@
-import { defineConfig } from '@playwright/test';
+import {
+    defineConfig,
+    devices,
+} from '@playwright/test';
+
+/**
+ * E2E config. Tests run against the production build via `vite preview` on port 4173.
+ * Locally: all three browser engines run in parallel.
+ * CI: chromium only, workers=1 — the runner has 6GB RAM and `yarn build` already
+ * spikes 1–2GB, so we keep the E2E peak bounded.
+ */
+const isCI = !!process.env.CI;
 
 export default defineConfig({
+    testDir: 'e2e',
+    testMatch: /.*\.test\.ts$/,
+
+    fullyParallel: true,
+    forbidOnly: isCI,
+    retries: isCI ? 2 : 0,
+    workers: isCI ? 1 : undefined,
+
+    reporter: isCI
+        ? [['html', { open: 'never' }], ['github']]
+        : [['html', { open: 'on-failure' }], ['list']],
+
+    use: {
+        baseURL: 'http://localhost:4173',
+        trace: 'on-first-retry',
+        screenshot: 'only-on-failure',
+        video: 'retain-on-failure',
+    },
+
+    projects: isCI
+        ? [{ name: 'chromium', use: { ...devices['Desktop Chrome'] } }]
+        : [
+            {
+                name: 'chromium',
+                use: {
+                    ...devices['Desktop Chrome'],
+                },
+            },
+            {
+                name: 'firefox',
+                use: { ...devices['Desktop Firefox'] },
+            },
+        ],
     webServer: {
         command: 'yarn build && yarn preview',
         port: 4173,
-        reuseExistingServer: true,
+        reuseExistingServer: !isCI,
+        timeout: 120_000,
     },
-    testDir: 'e2e',
 });