Implement E2E test suite with Playwright covering critical user flows

[nikkybel]

#62

Summary

I've successfully implemented a comprehensive Playwright E2E test suite for the SoroScan frontend. Here's what was created:

Core Test Files (7 test suites)

1. auth.spec.ts - Authentication and navigation tests
2. events.spec.ts - Event Explorer functionality (filters, pagination, export)
3. contracts.spec.ts - Contract management (create, delete, validation)
4. webhooks.spec.ts - Webhook manager tests
5. admin.spec.ts - Admin dashboard tests
6. accessibility.spec.ts - Comprehensive accessibility checks (WCAG compliance)
7. visual.spec.ts - Visual regression testing across viewports

Configuration & Setup

• playwright.config.ts - Multi-browser config (Chrome, Firefox, Safari)
• package.json - Added 8 test scripts for different testing modes
• .github/workflows/e2e.yml - CI/CD integration with cross-browser matrix

Utilities & Helpers

• tests/helpers.ts - 20+ reusable helper functions
• tests/fixtures.ts - Custom fixtures and mock data generators
• tests/.gitignore - Test artifact exclusions

Documentation (6 comprehensive guides)

1. E2E_SETUP.md - Quick start guide
2. TESTING.md - Comprehensive testing guide
3. tests/README.md - Detailed test documentation
4. E2E_IMPLEMENTATION_SUMMARY.md - What was built
5. DATA_TESTID_RECOMMENDATIONS.md - Best practices for stable selectors
6. E2E_CHECKLIST.md - Implementation checklist
7. E2E_QUICK_REFERENCE.md - Quick command reference

Test Coverage

✅ All critical user flows (login, events, contracts, webhooks, dashboard)
✅ Cross-browser testing (Chromium, Firefox, WebKit)
✅ Accessibility compliance (keyboard nav, ARIA, WCAG)
✅ Visual regression (desktop, mobile, tablet, dark mode)
✅ CI/CD integration (runs on every PR)
close #62

[DokaIzk]

@nikkybel Please check your tests