docs(cog-pose): correct misleading adapter cross-reference

The --adapter docs claimed the adapter is produced by
aether-arena/calibration/calibrate.py, but that reference tool targets the
MM-Fi *transformer* model and emits .npz with proj/head LoRA keys, while
this cog runs a *conv+MLP* model expecting safetensors with fc1.a/fc1.b/
fc2.a/fc2.b. Same LoRA mechanism, different model -> adapters are
model-specific and NOT interchangeable. Clarify the expected key layout and
that the Python tool is a mechanism reference, not a drop-in producer.
6/6 tests pass.

Co-Authored-By: claude-flow <ruv@ruv.net>