Add PhiSpiral256 Leaf Planetarium plan to ndarray index

Author: AdaWorldAPI

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

@@ -1,6 +1,6 @@
 # 3DGS Implementation Plan Index — ndarray
 
-This directory contains the ndarray-side implementation plans for the 3DGS geospatial rebuild and the PR-X12 tensor-container expansion line.
+This directory contains the ndarray-side implementation plans for the 3DGS geospatial rebuild, the PR-X12 tensor-container expansion line, and PhiSpiral256 leaf-location codec work.
 
 ## ndarray responsibility
 
@@ -12,6 +12,7 @@ This directory contains the ndarray-side implementation plans for the 3DGS geosp
 - EWA/SYRK/BLAS/MKL backend dispatch for large-batch covariance projection.
 - Domain-neutral certified field-kernel substrate pieces when repeated by multiple consumers.
 - PR-X12 tensor-container expansion kernels and benchmark hooks where they touch decode-during-GEMM.
+- PhiSpiral256 center generation, atom packing, distance/neighbor tables, and calibration kernels.
 - 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`.
@@ -51,6 +52,22 @@ Use inline code only for short identifiers such as `ndarray::hpc::splat3d` or `T
 3DGS-render-depth-certification-plan.md
 ```
 
+## PhiSpiral256 leaf-location plans
+
+```text
+PhiSpiral256-LeafPlanetarium-integration-plan.md
+```
+
+This plan keeps the lanes distinct:
+
+```text
+CAM_PQ       -> meaning / semantic basin lane
+PolarQuant   -> magnitude / similarity lane
+PhiSpiral256 -> orthogonal local residual location lane
+BGZ17        -> golden offset/stride recoverable sampling skeleton
+Fisher-z     -> optional statistical angular scorer/gate after candidate ranking
+```
+
 ## PR-X12 tensor-container capstone
 
 ```text
@@ -115,6 +132,16 @@ ndarray EWA/SYRK/BLAS backend selection
 batched covariance projection report
 ```
 
+For PhiSpiral256, the intended interface is:
+
+```text
+lance-graph leaf-location / SoA residual request
+        ->
+ndarray PhiSpiral256 encode / neighbor / distance / calibration kernels
+        ->
+packed orthogonal residual location atoms and calibration report
+```
+
 For certified field kernels, the intended interface is:
 
 ```text
@@ -135,4 +162,4 @@ ndarray PR-X12 block decode / codebook / GEMM-adjacent kernels
 cache-resident decode-during-GEMM report
 ```
 
-Central principle: renderer, codec, depth, and field-kernel decisions should be fast, inspectable, and mathematically auditable.
+Central principle: renderer, codec, depth, location, and field-kernel decisions should be fast, inspectable, and mathematically auditable.