feat: add virtual wallet injection & webServer config for E2E tests (#16)

[sandrawillow001-afk]

Changes

What was done

• playwright.config.ts — Added webServer auto-start config with reuseExistingServer: !!process.env.CI so the dev server starts automatically in local dev and reuses the CI-managed server in GitHub Actions
• tests/e2e/wallet.spec.ts — Added virtual wallet injection infrastructure and 7 new tests:
  • injectWalletSession() helper that navigates to the app, sets localStorage with a pre-configured auth session, and reloads — no Stellar SDK dependency
  • 5 virtual injection tests: verify connected state from injected session, specific addresses, disconnect clears state, reload persistence, expired session fallback
  • 2 edge case tests: corrupt localStorage graceful fallback, missing secret still shows address
  • All 7 original tests preserved intact
• eslint.config.mjs — Added test-results/** and playwright-report/** to ignore patterns
• .gitignore — Added Playwright output directories

Validation (all green)

Check	Result
E2E (Playwright)	14/14 passed
Unit (Vitest)	44/44 passed
TypeScript	0 errors
ESLint	0 errors/warnings
Build (npm run build)	Passed

Full CI pipeline

npm run build && npm test && npx playwright test

All three stages pass clean.
closes #37

[elizabetheonoja-art]

LGTM