ogar-fma-skeleton: wire bones to the Located-primary Guid (3-axis CRS)

Each bone now resolves to a 16-byte Guid (the [256:256] container:member
tier model), Located-primary since bones ARE the position anchor:

  classid  = 0x0A03 (Anatomy:bone)
  HEEL/HIP = the rest-pose 3-axis CRS — HEEL coronal x:y, HIP depth z
             (located_heel_hip) — ArcGIS/Cesium-addressable, so the body is
             a GIS layer and ViT / ultrasound×Doppler project onto the same
             coordinate
  LEAF     = familyNode:identity = [bodypart:bone] — the parent group is the
             family (identity 0 IS the group's family node; identity >=1 are
             its bones)

same_family now keys on classid + leaf family_node (mode-agnostic): in
Located mode the spatial HHTL is the orthogonal location axis, so two
same-family bones sit at different positions. is_ancestor walks parent
links (partonomy), not an address prefix.

Tests rewritten for the Guid model (24 pass): classid tier, HEEL laterality
(left/right femur differ in HEEL, same family, different identity), HIP
depth (sternum anterior vs vertebra posterior), unique node keys + leaves,
family-node grouping with attached identity, parent-link ancestry, clamped
anchors, unit quaternions, classid stability. clippy-clean.

Morton primitives + FamilyAddress stay in morton.rs as the value-side
splat-refinement tool. Crate docs updated to the Guid model.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EYvNjD8M8LMNYbRy3gq2FP

Author: claude

crates/ogar-fma-skeleton/src/guid.rs

@@ -167,13 +167,15 @@ impl Guid {
         self.bytes[2 * TIER_LEAF + 1]
     }
 
-    /// `true` if `self` and `other` are in the **same family**: every tier up
-    /// to and including the leaf's `family_node` agrees; only the leaf
-    /// `identity` differs. This is "identity attached to family node" — the
-    /// family node is the routing prefix, the identity discriminates within.
+    /// `true` if `self` and `other` are in the **same family**: same `classid`
+    /// and same leaf `family_node`. This is "identity attached to family node"
+    /// — the family node groups, the leaf `identity` discriminates within. It
+    /// is mode-agnostic: in Located mode the spatial HHTL is an *orthogonal*
+    /// location axis (two same-family bones sit at different positions), so
+    /// family grouping keys on the categorical leaf byte, not the HHTL prefix.
     #[must_use]
     pub fn same_family(&self, other: &Self) -> bool {
-        self.bytes[..2 * TIER_LEAF + 1] == other.bytes[..2 * TIER_LEAF + 1]
+        self.classid() == other.classid() && self.family_node() == other.family_node()
     }
 }
 
@@ -204,6 +206,23 @@ pub fn spatial_tier(x: u8, y: u8) -> Tier {
     }
 }
 
+/// Encode a 3-axis body position into the Located `(HEEL, HIP)` spatial tier
+/// pair — an ArcGIS / Cesium-addressable coordinate reference system.
+///
+/// - **HEEL** = coronal `(x : y)` 2D-Morton (anatomical-left × superior) — the
+///   plane an X-ray or anterior-ultrasound sweep projects onto.
+/// - **HIP** = depth `(z)` — anterior-posterior, the imaging *slice* axis.
+///
+/// Prefix containment over `HEEL ++ HIP` is therefore 3-axis spatial
+/// containment: a quadkey/octant the GIS stack can `contains` / `buffer` /
+/// page by LOD. v0 fence: this is *coronal-tile + depth-slice* (exactly how
+/// medical imaging is organised), not yet a single interleaved 3D octree —
+/// HIP's odd (Y) bits are reserved for a finer refinement axis.
+#[must_use]
+pub fn located_heel_hip(x: u8, y: u8, z: u8) -> (Tier, Tier) {
+    (spatial_tier(x, y), spatial_tier(z, 0))
+}
+
 /// The **mode** of an HHTL tier — the operator's "heel" distinction
 /// (2026-06-23).
 ///