Correct full-length 5-seed mean cells in the model card to match the released checkpoints

Update v2 five-seed checkpoints to the latest code (commit 11dae9c); refresh config, model card, and checksums

Add v2 five-seed checkpoints (full-length, V3-V4, V4) with per-region defaults, updated config and model card

List SHA-256 checksums for all three checkpoints

Cite the Bioinformatics Advances paper instead of a software entry

Add V4 (515F/806R) checkpoint: model weights, config variant, and model card

Initial commit