Document the complete 500-step release series

Update milestone inventory through step 510

Update milestone inventory through step 510

Publish step 510 merge manifest

Rewrite model card for reader-facing clarity

Add release checksums

Upload S020 v1 step-510 rank-64 LoRA

Upload S020 v1 step-510 merged FP8 text encoder

Add technical model card and step-510 release metadata

initial commit