Adds the v2 forward kernel cubins (layer_norm, variable_selection,
attention_pool) and function handles (vsn_fwd_fn, ln_fwd_fn, attn_fwd_fn,
snap_batched_fn, step_batched_fn, heads_grn_fwd_fn, transpose_3d_fn)
onto CfcTrunk. The trunk now owns every kernel handle the v2 forward
chain needs.
PerceptionTrainer still loads its own copies of these cubins (duplicate
loading) and uses its own handles in evaluate_batched / step_batched —
the trainer-side consolidation lands in X10b. This commit is the
foundation: X11 will build capture_graph_a using these trunk-owned
handles, and X12 (CheckpointV2) doesn't depend on the consolidation.
Verification:
- perception_forward_golden: PASS (max_diff = 0.000000)
- ml-alpha lib tests: 34 pass
Per spec §2.2 (X10).