ROS bring-up notes

A compact mobile base needed reliable transforms and repeatable launches before autonomy work could start. Sim looked fine; hardware needed the same assumptions spelled out explicitly.

We standardized launch files per robot profile, added sanity checks for the TF tree, and logged frame IDs whenever a node published odd transforms.

Sim-to-real gaps showed up as timing and wheel slip rather than missing topics — documenting that saved the next integration pass.