Borrow [M, inFeatures] and axis-0 weights; return owned lazy [M, outFeatures].
The caller selects a supported variant and limits M to 1..4. representation
applies where scatterBitsEligible holds; layers pass the one they resolved
at construction (qualifiedRepresentations), benches and tests the one they compare.
Borrow [M, inFeatures] and axis-0 weights; return owned lazy [M, outFeatures]. The caller selects a supported variant and limits M to 1..4.
representationapplies wherescatterBitsEligibleholds; layers pass the one they resolved at construction (qualifiedRepresentations), benches and tests the one they compare.