scripts/2026-09-15_v6_T12_sim_dual_footprint.py moves the U22 edits into the
T-script chain. Idempotent, dry-run by default, .T12bak backups, UUID invariant
guard, and a gate-0 assertion on the MFF2 land pattern. Verified to reproduce the
hand edits byte-for-byte. Part 2 (nano-SIM holder + 0R selects) pending the
holder datasheet.
