isv_forward kernel: temporal decay-weighted average + 8->16->8 MLP. Outputs: isv_embedding [8], branch_gate [4] (softmax), gamma_mod [1] (0.5+0.5*sigmoid -> [0.5,1.0]). NUM_WEIGHT_TENSORS: 68->78. 10 new tensors for ISV encoder, gate, gamma, and confidence head. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>