Delegate threshold param parsing to the new DeviceAttachmentSpec primitives
so intrin modules stay aligned with stimBuff param conventions.
Co-authored-by: Cursor <cursoragent@cursor.com>
We now specify intrins as separate DAPS lines. This syntax is much
nicer and well-grouped than the previous negtrin-*/postrin-* param
names.
Alas, we're about to replace it in the next few commits already though.