## Summary
- add an opt-in `sv_struct_field_ordering` policy for `dslx2sv-types`
- thread the policy through the SV bridge and driver surface without
changing existing defaults
- document that `reversed` changes packed SV layout, and fix the README
example to use `--dslx_input_file`

## Validation
- `cargo test -p xlsynth --test sv_bridge_test`
- `XLSYNTH_TOOLS=/opt/eda-tools/xlsynth/latest cargo test -p
xlsynth-driver --test invoke_test dslx2sv_types`

## Landing
This is the provider-first PR for the struct-ordering rollout.
`rules_xlsynth` will stack on this behavior, and Chili will consume it
downstream.