E2E Playwright Testing Patterns and conventions for reliable end-to-end browser testing with Playwright. Comprehensive E2E testing guide for web applications. Contains 8 rules across 6 categories covering locator strategies, authentication reuse, form testing (including React/SPA-specific gotchas), assertions, test organization, reliability, and CI/CD configuration. Stack Detection Before writing or reviewing E2E tests, detect the project stack: Step 1 — Check for Playwright - If is present → use Playwright patterns from this skill - If is present → this skill does not apply Step 2 — Detect F…