The flag enables a second power supply (VAPWR), not necessarily 3.3V (gf180's core is already 3v3), so "uses_3v3" no longer accurately describes its purpose.
Rename it across project_info, precheck, project and shuttle, and update the validation message accordingly.
The legacy "uses_3v3" key is still accepted when reading info.yaml, so existing project configs keep working.
- no shapes outside project area
- VPWR/VGND present, VAPWR present iff uses_3v3
- no invalid layers
- cell names don't have '#' or '/'
- urpm to nwell spacing satisfies DRC
- analog pins have adjacent metal iff marked as used
htfab