Roadmap orthogonal categories — moved

Consolidated into docs/PLAN.md. Several markers in the old version were stale; the merged doc is verified against code.

Roadmap — orthogonal categories

Absorbed into the master plan. The old version of this file marked Lion/Sophia/Muon/Adafactor and the full PEFT bundle (VeRA/LoftQ/AdaLoRA/RsLoRA/PISSA/LoRA-FA) as ⬜ — they’re all shipped. The merged doc fixes those markers against the codebase.