New skill that collects real financial data for any US publicly traded company
via yfinance. Outputs structured JSON with market data, historical financials,
WACC inputs, and analyst estimates. Includes 9-check validation script and
reference docs for yfinance pitfalls (NaN years, field aliases, FCF mismatch).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>