CHANGELOG update

Author: Baraa-Elmoussa

CHANGELOG.md

@@ -13,6 +13,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+* Replaced kernel-layer `MatrixConstraint` with standard `pyo.Constraint` rules in `static_equilibrium_constraints` for compatibility with recent Pyomo versions.
+* Pinned Python to `< 3.14` for viewer compatibility.
+
 ### Removed