❌ U2 still fails Missing Footprints DRC (so it cannot be reliably placed/routed on PCB until a footprint-backed library entry is used).
❌ Cannot place U2 at the board edge or create the 10 mm antenna keep-out via tools (placement/keep-out geometry are PCB-editor actions).
❌ Cannot route/convert all ratsnest lines into copper traces via tools; DRC still shows Airwires.
✅ Power and SWD nets for U2 and J2 are now correctly connected in the schematic netlist.
Next steps
Replace U2 with a Flux library entry that includes a valid PCB footprint (castellated + integrated antenna). Once U2 has no footprint error, you can place it at the board edge and enforce the 10 mm keep-out.
In PCB editor: place U2 at the edge (antenna outward), draw the 10 mm keep-out, pour bottom GND, and run Auto-Layout/routing to clear Airwires (then re-check DRC).