test(auth,payments,subs): add 58 unit tests for critical auth, payment, and subscription paths

Cover auth handlers (RegisterUser, LoginUser, RefreshToken), TokenService
(token rotation, reuse attack detection), payment callback edge cases
(duplicate/concurrent callbacks, multi-provider), subscription lifecycle
transitions (expire, pastDue, renew), and throttler proxy guard.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

playwright.config.ts

@@ -1,4 +1,11 @@
+import path from 'node:path';
 import { defineConfig, devices } from '@playwright/test';
+import { config } from 'dotenv';
+
+// Load .env.test so webServer processes and tests use the test database
+if (!process.env.CI) {
+  config({ path: path.resolve(__dirname, '.env.test'), override: true });
+}
 
 /**
  * Playwright E2E configuration for Goodgo Platform.
@@ -6,9 +13,15 @@ import { defineConfig, devices } from '@playwright/test';
  * Projects:
  *   - "api" — tests against the NestJS API (port 3001)
  *   - "web" — tests against the Next.js frontend (port 3000)
+ *
+ * Database isolation:
+ *   - globalSetup runs migrations + seed on the test DB
+ *   - globalTeardown cleans up test-generated data after all tests
  */
 export default defineConfig({
   testDir: './e2e',
+  globalSetup: './e2e/global-setup.ts',
+  globalTeardown: './e2e/global-teardown.ts',
   fullyParallel: true,
   forbidOnly: !!process.env.CI,
   retries: process.env.CI ? 2 : 0,
@@ -50,6 +63,7 @@ export default defineConfig({
       timeout: 60_000,
       env: {
         NODE_ENV: 'test',
+        DATABASE_URL: process.env.DATABASE_URL ?? '',
       },
     },
     {