docs(perturbation-sim): correct SIMD labels — AVX-512 (v4) yes, AMX no

The ndarray-simd Walsh-Hadamard path uses AVX-512 under x86-64-v4 — NOT AMX.
AMX is int8/bf16 tile-GEMM (ndarray::hpc::amx_matmul); this crate's WHT is f32
and its field tier f64, neither of which maps to AMX tiles. Corrected the loose
'AVX-512/AMX' wording in Cargo.toml/README/METHODS §10; noted the int8 AMX path
(matmul_i8_to_i32) as a possible-but-unwired future option.

Author: claude

crates/perturbation-sim/Cargo.toml

@@ -11,7 +11,8 @@ description = "Spectral + edge-propagation outage simulator: models the perturba
 #   cargo run   --manifest-path crates/perturbation-sim/Cargo.toml --example simulate
 [features]
 # Route the Morton/Walsh pyramid transform through ndarray's SIMD
-# (AVX-512/AMX, x86-64-v4) Walsh–Hadamard. Default OFF → the crate stays
+# (AVX-512 under x86-64-v4) Walsh–Hadamard. AMX is int8/bf16 tile-GEMM and is
+# NOT used (this crate's WHT is f32, its field tier f64). Default OFF → stays
 # zero-dep with the scalar `fwht` fallback. Build accelerated with:
 #   RUSTFLAGS='-C target-cpu=x86-64-v4' cargo … --features ndarray-simd
 # (or target-cpu=native locally). All SIMD comes from `ndarray::simd` per the

crates/perturbation-sim/METHODS.md

@@ -327,7 +327,10 @@ turning a modeling assumption into a testable claim.
 
 ### `ndarray-simd` feature (the Morton-pyramid transform, accelerated)
 The pyramid's Walsh–Hadamard transform routes through **`ndarray::simd::wht_f32`**
-(AVX-512/AMX under `target-cpu=x86-64-v4`) — the one workspace-sanctioned SIMD
+(AVX-512 under `target-cpu=x86-64-v4`; **AMX is NOT used** — AMX is int8/bf16
+tile-GEMM, whereas the WHT is f32 and the field tier f64. An int8 AMX path
+(`ndarray::simd::matmul_i8_to_i32`) for a quantized resistance sketch is a
+possible future wiring, not present) — the one workspace-sanctioned SIMD
 source (never raw intrinsics here). Default **OFF** → scalar `fwht`, zero-dep;
 **ON** via `--features ndarray-simd` (ndarray fork as a git/path dep, `["std"]`).
 Both paths pass the same tests. Deeper *tile-specific* ndarray targets, to wire

crates/perturbation-sim/README.md

@@ -15,7 +15,7 @@ method:
 | **Data-shaped scoping** | run on today's data; `assess_capability` gates which outputs are valid; missing variables modeled as uniform constants (provably free for relative results); `AgeModel` = Uniform null vs DensityProxy Gegenhypothese (topology-only) vs ModernizationSpend (official planning data). | `model.rs` |
 
 > **SIMD:** the Morton/Walsh pyramid transform optionally routes through
-> `ndarray::simd::wht_f32` (AVX-512/AMX) via `--features ndarray-simd`
+> `ndarray::simd::wht_f32` (AVX-512 under x86-64-v4; AMX not used — f32 WHT, not int8 tile-GEMM) via `--features ndarray-simd`
 > (`RUSTFLAGS='-C target-cpu=x86-64-v4'`); default is the zero-dep scalar path.
 > All SIMD comes from `ndarray::simd` (workspace rule). See `METHODS.md §10`.