Reconcile Newton 1.5.1 changelog (#4073)

Author: jcarius-nv

CHANGELOG.md

@@ -4,6 +4,16 @@
 
 <!-- towncrier release notes start -->
 
+## [1.5.1] - 2026-08-27
+
+### Fixed
+
+- Reset masked `ControllerNeuralLSTM` hidden and cell state without in-place writes. Network outputs are produced under `torch.inference_mode()`, so a partial reset previously raised `RuntimeError: Inplace update to inference tensor outside InferenceMode is not allowed.` ([#3923](https://github.com/newton-physics/newton/issues/3923))
+- Index Torch neural controller targets with the supplied `target_pos_indices`. `ControllerNeuralMLP` and `ControllerNeuralLSTM` previously selected between position and sequential indices by Python object identity, which produced wrong position errors whenever the target and position layouts differ, such as DOF-layout targets on a floating-base robot. ([#3923](https://github.com/newton-physics/newton/issues/3923))
+- Limit the `usd-exchange` dependency to versions below 3 for aarch64 systems. (#3996)
+- Keep ViewerGL depth, shading, and shadows stable for very large meshes when the camera moves. ([#3977](https://github.com/newton-physics/newton/issues/3977))
+- Resolve deep heightfield contacts against the cell's physical surface instead of the volume the cell is extruded into, which reported about a metre of penetration with a normal pointing into the terrain once a collider's center passed below the surface.
+
 ## [1.5.0] - 2026-08-11
 
 ### Added