Kev-0.8B round 15: documents + skills in one delta

Kev-0.8B: dates+unknowable delta (locked test 0.834 / 0.684); previous weights at tag v7-base

Kev-0.8B: Qwen3.5-0.8B-Base, decision-v7 recipe (locked test 0.827 / 0.668)