pinv(::DiagonalTensorMap) atol/rtol defaulting is inverted #545

Defaulting logic is backwards vs. LinearAlgebra.pinv and this repo's own convention (linalg.jl:288): atol==0 disables rtol entirely (no truncation at all — reproduced: near-zero singular value inverts to ~1e14 instead of being zeroed), while passing atol>0 force-enables an unrequested rtol and ignores an explicitly passed rtol. Also throws on a zero-dimensional tensor (maximum over empty collection).

src/tensors/diagonal.jl:366-378.