T002: Create __init__.py in tests/e2e/playwright/mcp/

## Task Description
Create Python package init file for MCP test directory.

## Phase
Phase 1: Setup (Shared Infrastructure)

## Details
- Create `tests/e2e/playwright/mcp/__init__.py`
- Can run in parallel with other setup tasks [P]

## Acceptance Criteria
- File exists and directory is a valid Python package

## Related Feature
Feature: 006-playwright-mcp-e2e