Consider a full-rank convenience view for SymmetryGroup generators

[spMohanty]

Summary

SymmetryGroup currently stores generator literals together with a separate axes tuple. That is fine for the core API, but it can be awkward for inspection/debugging because the generators are local to axes, not full-rank.

Example:

import whest as we

G = we.SymmetryGroup.young(((2, 3),))
print(G)
# SymmetryGroup([1, 0], axes=(2, 3))

For some workflows it would be more convenient to expose either:

• a num_axes / full-rank construction form, or
• a convenience method that returns generators re-indexed onto tuple(range(num_axes))

For example:

• current: SymmetryGroup([1, 0], axes=(2, 3))
• possible convenience view: SymmetryGroup([0, 1, 3, 2], num_axes=4)

Notes

This is an interface ergonomics request, not a correctness bug.

It should stay out of #51 unless the change can be made without reopening the symmetry API design.