bb_example_still_v2 and bb_example_video_v2: the calibrated still's and clip's cameras.json migrated from vgio/cameras/v1 to vgio/cameras/v2 with VisualGeometryIo.migrate_v1 (verified record for record against the v1 read; a camera carries no detector pixels, so nothing is relabelled). Media unchanged. Add-only: the v1 artifacts stay as they were.
Board definitions migrated to the v1 bundle schema (identity-preserving)
