fix(loss): include all views in LeJEPA SIGReg and invariance loss (#2002) (#2023)

* fix(loss): include all views in LeJEPA SIGReg and invariance loss (#2002)

* refactor(lejepa): rename local_proj parameter to all_proj in lejepa_invariance_loss and update docs

* docs(lejepa): address review nits in docstrings

* fix(lejepa): validate view shapes before concatenating

torch.cat ran first, so mismatched local_proj/global_proj raised
RuntimeError instead of ValueError, and the checks inside
lejepa_invariance_loss were vacuous once all_proj was built from
global_proj.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* docs: note that LeJEPA benchmark numbers predate the loss fix

The ImageNet run was published before SIGReg and the invariance term
covered the global views, so the tables no longer match what the
benchmark script produces.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: gabrielfruet <gabrielfruet538@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>