nx_select.nx

nx_select.nx -- single-class variant selector engine. SA-4 milestone of NISHI_SELF_ASSEMBLY_ROADMAP.md. Consumes (candidates, probe, calibration, policy) and returns the index of the best-match variant under the policy vector subject to the candidate's requires_* constraints intersecting the device's probe. Selection function (single-class, MVP): S(C, P, K, π) = argmin_{v ∈ candidates} Σ_axis π[axis] · cost_axis(v) · K[axis_norm] s.t. requires_isa(v) ⊆ P.actual_isa_family requires_isa_ext(v) ⊆ P.actual_isa_ext requires_ram_min(v) ≤ P.ram_proxy tier_floor(v) ≤ K.inferred_tier tier_ceiling(v) ≥ K.inferred_tier Joint-DAG cross-primitive selection deferred to SA-5 (nx_select_joint). Per-primitive smoke gating deferred to SA-6 (nx_verify). Byzantine N-of-M deferred to SA-7. V1 manifest schema is INTEGER-ENCODED (sealed-enum bitmasks for requires_isa, Q10 fixed-point for cost coefficients) so the selector runs without a manifest-header parser. SA-5 lands the parser that lifts authored headers in `runtime/*.nx` into these integer-encoded records. genealogy_id: petabricks_2009 + halide_schedule_search_2019 + cardinal_2026-05-19_self_assembly lineage_id: substrate_select_v1 nx_capability_manifest: variant_class: capability_select variant_id: capability_select_v1_single_class requires_isa: [rv64imac, x86_64] requires_syscalls: [mmap] requires_ram_min_b: 4096 tier_floor: NX_TIER_MOBILE tier_ceiling: NX_TIER_HPC cost_model: