Update README.md

Panel complete: freqnet, cavia2024, d3 final -- all 13 detectors ready

spai final (val AUC 0.9998)

ojha2023 final (val AUC 0.9973)

corvi2023 final (val AUC 1.0000)

npr2024 final (val AUC 1.0000); corvi2023/spai provisional updates; note ojha2023 retry

add AIDE/Effort/C2P-CLIP/AlignedForensics released checkpoints + SPAI row

remove recipe table; add DRCT rows; document panel gaps

remove citation section

Model card: GenImage-SD1.4 controlled detector panel