feat(freecell): classic FreeCell with Microsoft-style deals

Summary

Adds FreeCell (src/freecell/) — classic Microsoft-style FreeCell with deal numbers, free cells, cascades, foundations, supermoves, and auto-home.

Logos

Master artwork downsampled with sharp to icon.png (1024), icon-128.png, and public/icon-{128,192,512}.png.

Comparison

DOCUMENTED vs Windows FreeCell in src/freecell/README.md (deal #1 tops match Rosetta: JD 2D 9H JC 5D 7H 7C 5H).

Tests

cd src/freecell && npm test — 10 passed; npm run build OK

Original code only — no Microsoft assets.