Fix isort indentation format

[isort] Format the imports in the "hanging Indent" style

[CI] Upgrade tj-actions/changed-files to v46 to fix security issues

Adjust autotuning args

Fix shape mismatch when saving block indices

Support varlen mean pooling compression

Reuse the toml config in `flame`

Fix offset bugs for compressed kv

Autotune args for better performance

[README] Add training support

Use `flash_attn` for swa

Merge `parallel_nsa` with `parallel_nsa_with_compression`

Update default configs for training

Add training scripts

Update default configs for 340M models