Croissant: place rai:hasSyntheticData near top + add unprefixed alias for validator compatibility

Fix RAI field name: rai:syntheticDataIndicator -> rai:hasSyntheticData (boolean) per official Croissant RAI spec

Croissant 1.1: validated by mlcroissant 1.1.0 (0 errors), HF parquet structure + RAI fields + datePublished

Sync Croissant URL to anonymous.4open.science

Update repo URL to anonymous.4open.science (anonymity hardening)

Initial dataset release: TSFMI-Synthetic (11 configs, 60/20/20 splits, Croissant 1.0 + RAI metadata)

initial commit