Add a 'computer use' section to skill.md showing how Playwriter covers all
actions from the Anthropic computer_20250124 tool and the Claude Chrome
extension's custom computer tool, using Playwright APIs instead of
screenshot-based coordinate clicking.
Each subsection shows the declarative locator-based approach first (preferred)
with coordinate-based fallback for canvas/maps/custom widgets.
Also adds docs/claude-extension-tools.json with all 16 tool schemas extracted
from the Claude Chrome extension v1.0.39 (minified source) for reference.