cpl: hold 7Q9B as PDB, and correct 868's cognate in the notes

cpl: add the sb27 cognate model, completing 7 of 7 clones

Upload cpl/cpl_native_structures.tar.gz with huggingface_hub

Add CPL per-structure AF/TCRmodel confidences + DockQ (cpl_data_stats_new_struct.tsv)

Finalize CPL: all 7 clones as one archive (adds 868, sb27)

cleanup: remove notebooks/figures/analysis-tables from cpl/ (structures + descriptions only)

CPL strong/weak binder structures + tables + PWMs (tcren2)