Function validate_solver_input 

pub fn validate_solver_input(
    matrix: &CsrMatrix<f32>,
    rhs: &[f32],
    tolerance: f64,
) -> Result<(), ValidationError>

Validate the complete solver input (matrix + rhs + parameters).

This is a convenience function that calls validate_csr_matrix, validate_rhs, and validates tolerance in sequence. It also checks that the matrix is square, which is required by all iterative solvers.

Errors

Returns ValidationError on the first failing check.