Add certified field kernel substrate plan to ndarray index

Author: AdaWorldAPI

.claude/plans/3DGS-PLAN-INDEX.md

@@ -9,6 +9,7 @@ This directory contains the ndarray-side implementation plans for the 3DGS geosp
 - CPU-SIMD 3D Gaussian Splatting forward renderer.
 - SPD covariance construction and EWA projection math.
 - EWA/SYRK/BLAS/MKL backend dispatch for large-batch covariance projection.
+- Domain-neutral certified field-kernel substrate pieces when repeated by multiple consumers.
 - Pillar-certified error probes under `src/hpc/pillar`.
 - Columnar splat payload formats and quantization carriers.
 - HHTL / HEEL-HIP-TWIG-LEAF selection primitives callable by `lance-graph`.
@@ -44,11 +45,12 @@ Use inline code only for short identifiers such as `ndarray::hpc::splat3d` or `T
 3DGS-validation-benchmark-plan.md
 3DGS-4x4-cognitive-shader-SoA-plan.md
 3DGS-EWA-SYRK-BLAS-MKL-crosspollination-plan.md
+3DGS-certified-field-kernel-substrate-plan.md
 ```
 
 ## Cross-repo boundary
 
-`ndarray` should not own 3D Tiles, Cesium compatibility, ArcGIS service ingestion, graph query planning, SplatShaderBlas orchestration, or tile serving. Those live in `lance-graph`.
+`ndarray` should not own 3D Tiles, Cesium compatibility, ArcGIS service ingestion, graph query planning, SplatShaderBlas orchestration, datalake semantics, domain adapters, or tile serving. Those live in `lance-graph`.
 
 The intended interface is:
 
@@ -80,4 +82,14 @@ ndarray EWA/SYRK/BLAS backend selection
 batched covariance projection report
 ```
 
-Central principle: renderer decisions should be fast, inspectable, and mathematically auditable.
+For certified field kernels, the intended interface is:
+
+```text
+lance-graph domain adapter / datalake block summary
+        ->
+ndarray field-kernel scoring/certification kernels
+        ->
+behavior-affecting certificate summary
+```
+
+Central principle: renderer and field-kernel decisions should be fast, inspectable, and mathematically auditable.