Function updateInstancedLinesMesh

updateInstancedLinesMesh(
mesh: Mesh,
meshConfig: InstancedLinesMeshConfig,
): boolean
Update an existing instanced lines mesh with new segment data.

Mirrors the non-pool points commit path (texture-storage era):
- Same count: in-place fused texel write into the existing line texture (zero GPU re-allocation; ranged upload) + identity ordering reset.
- Different count: build a FRESH geometry (the non-pool storage is exact-size) and dispose the old one — never rebind new storage onto a rendered geometry, which strands the old GPU resources in the renderer caches (freed only at GC mercy on classic WebGL; pinned FOREVER by the WebGPU renderer's strong Info.memoryMap).
- Colormap toggles no longer rebuild anything: the fixed 6-texel layout always carries the scalar slots.
- Always: recompute bounding box/sphere + refresh the scalar presence stamp.
Parameters
- mesh: Mesh
  Existing mesh to update (must have InstancedBufferGeometry)
- meshConfig: InstancedLinesMeshConfig
  New segment data
Returns boolean
true when the geometry was REBUILT (size change) — the caller must then evict Three's cached RenderObject (see invalidate-render-object.ts); false for the in-place write.
- Defined in src/rendering/line-geometry.ts:577