test(e2e): add comprehensive E2E tests for listings, search, payments, subscriptions, admin

Expand Playwright E2E test coverage from 17 to 86 tests covering:
- Listings CRUD (create, search, filter, detail, status update)
- Search (text search, geo search, validation, Typesense fallback)
- Payments (create, list transactions, auth guards)
- Subscriptions (plans, create, quota, billing, usage metering)
- Admin authorization guards (all endpoints reject non-admin users)

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

e2e/fixtures/index.ts

@@ -1,3 +1,4 @@
 export { test, expect } from './auth.fixture';
 export { createTestUser, registerUser, loginUser } from './auth.fixture';
 export type { TokenPair } from './auth.fixture';
+export { createTestListing, createListing } from './listings.fixture';