feat: add browser automation tool via Playwright

[NSIETeam]

What

Adds a new web_automation tool with 9 browser automation actions via Playwright.

Actions

Action	Description
navigate	Navigate to URL, wait for network idle
fill	Fill a form field with text (CSS selector)
click	Click an element, optionally wait for navigation
scrape	Extract text/html/href/src from element
extract_table	Extract table data as 2D array
screenshot	Capture viewport or full-page screenshot
run_script	Execute custom JavaScript on page
wait	Wait for element to appear
list_tabs	List all open browser tabs

Features

• Session persistence: Saves/restores browser state (cookies, localStorage) between actions via storageState
• Cross-platform: Works identically on macOS, Windows, Linux via Playwright
• Dependency check: require.resolve('playwright') before execution, with clear install instructions
• Safety: All actions require user confirmation (touches external systems); YOLO mode skips

Dependencies

• playwright npm package
• npx playwright install chromium (one-time browser download)

Origin

Ported from Otto project. Adapted for EasyCode:

• Removed ProcessGuard dependency, uses child_process.exec
• Removed DoctorService dependency, uses inline require.resolve
• Same API surface and behavior

Testing

• TypeScript compiles
• Integration tests (requires Playwright + browser)