Two new datasets with source catalogs (DS-00019, DS-00020): - DE-Wealth-Distribution: Wealth Gini 72.4% (PHF 2023), top shares, inheritance - EU-Wealth-Inequality: Cross-country Gini comparison (50.8–72.6) Updated README.md, Data/README.md, QUICK_REFERENCE.md to document all 24 datasets (7 US + 16 DE + 1 EU), 20 source catalogs, and DE-Plan integration. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>