* feat: add sageattention
* feat: call path on pre model load
* fix: patch to use register to correct var
* fix: add strict check import at start
* chore: fix comments
* chore: refactor
* feat: add capability check
* fix: missed underscore
* fix: let sageattention use FA backend in transformers
* feat: update sage attention for attention mask and position ids
* feat: allow sample packing but add warning without packing
* fix: loss hitting 0 with packing and attention mask note
* feat: downcast embeds if sage attention too
* feat: add config validation
* feat: add attention docs
* chore: docs
