B-8: Comprehensive E2E test suite with Playwright

[KuchiMercy]

Summary

Playwright configuration exists in the backend test directory, but the E2E test suite is minimal. As the platform grows, comprehensive end-to-end tests are essential to prevent regressions on critical user flows.

Requirements

• Write E2E tests covering the following critical flows:
  1. Wallet authentication: Challenge request, signature verification, JWT issuance, token refresh
  2. Escrow happy path: Create escrow -> invite parties -> fund -> release milestones -> complete
  3. Dispute flow: Create escrow -> fund -> file dispute -> admin resolves -> funds distributed
  4. Deadline expiration: Create escrow with deadline -> time passes -> auto-expire via scheduler
  5. Party acceptance: Invite party -> party accepts -> all parties accepted -> escrow activatable
  6. Admin operations: List users, list escrows, view audit logs, resolve disputes
  7. Error paths: Duplicate funding, unauthorized access, invalid state transitions, expired escrow operations
• Mock the Stellar RPC and blockchain interactions for deterministic test execution
• Set up test database fixtures with seed data
• Target 80%+ coverage of API endpoints
• Configure CI-compatible test execution (headless, parallel where possible)

Acceptance Criteria

• All 7 test suites listed above pass consistently
• Stellar RPC is mocked — no real network calls during tests
• Test database is seeded and torn down per test suite
• Tests can run in CI without manual intervention
• No flaky tests (run 3x in CI to verify stability)
• Test report shows endpoint coverage percentage
• Tests complete in under 2 minutes total

Context

• Playwright config: apps/backend/test/
• Existing unit tests: Jest-based across modules
• Backend entry: apps/backend/src/main.ts
• Auth flow: apps/backend/src/modules/auth/auth.controller.ts

Rollout Phase

Phase 5 — Admin & Production Hardening

Points: 150 (Medium)