Function solve 

pub fn solve<const NU: usize, const NV: usize, const NC: usize>(
    a: &MatA<NC, NU>,
    b: &VecN<NC>,
    umin: &VecN<NU>,
    umax: &VecN<NU>,
    us: &mut VecN<NU>,
    ws: &mut [i8; NU],
    imax: usize,
) -> SolverStats
where
    Const<NC>: DimName + DimMin<Const<NU>, Output = Const<NU>>,
    Const<NU>: DimName,
    Const<NV>: DimName,
    DefaultAllocator: Allocator<Const<NC>, Const<NU>> + Allocator<Const<NC>, Const<NC>> + Allocator<Const<NU>, Const<NU>> + Allocator<Const<NC>> + Allocator<Const<NU>>,

Active-set solver with incremental QR updates via Givens rotations.

Uses nalgebra’s Householder QR for the initial factorisation, then Givens column-shift updates when constraints activate/deactivate.

Translates solveActiveSet_qr.c.