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>

package.json

@@ -50,7 +50,9 @@
   "devDependencies": {
     "@eslint/js": "^9.39.4",
     "@playwright/test": "^1.59.1",
+    "@types/pg": "^8.20.0",
     "dependency-cruiser": "^17.3.10",
+    "dotenv": "^17.4.1",
     "eslint": "^9.39.4",
     "eslint-config-prettier": "^10.1.8",
     "eslint-import-resolver-typescript": "^4.4.4",
@@ -58,6 +60,7 @@
     "globals": "^17.4.0",
     "husky": "^9.1.7",
     "lint-staged": "^16.4.0",
+    "pg": "^8.20.0",
     "prettier": "^3.8.1",
     "prisma": "^7.7.0",
     "tsx": "^4.21.0",