fix(linalg): refuse non-finite input in dense Cholesky, Eigen and rank-one updates

Assisted-by: GLM 5.3 Flash

CHANGELOG.md

@@ -5,6 +5,17 @@ All notable changes to **Tensor** are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [development]
+
+### Fixed
+
+**Linear algebra.**
+
+- `Cholesky`, `Eigen`, `EigenComplex` and the Cholesky rank-one
+  update refuse a matrix or vector holding a NaN or infinity instead
+  of returning an all-NaN factor or spectrum with a nil error, the
+  refusal the sparse solvers already make.
+
 ## [1.0.0] - 2026-09-03
 
 The initial release of Tensor, a scientific computing library in pure