Initialise E2E Test Suite

Scaffold the entire e2e/ directory structure with all configuration files, base classes, fixtures, and helpers needed to start writing Playwright E2E tests.

Pre-Flight Check

1. Check if e2e/ already exists. If so, abort and inform the user — do NOT overwrite an existing test suite.
2. Check if Playwright is installed. If @playwright/test is not in package.json, add it.

Workflow

Step 1 — Create the Directory Structure

e2e/