Antenna-rule fixing

Antenna-rule fixing. Each net's antenna is the run of metal connected to its gate, drawn as a bar on the layer it runs on (the faint lines above it are the higher layers). During fabrication a metal run that is too long collects charge that can damage the gate, so any net whose bar passes the dashed limit (red) must be fixed. There are two fixes, and which one a net needs is physical:

• Layer jump carries the far part of the metal up to the next layer, leaving only a short stub on the gate's layer. It needs a layer above to jump to, so a net whose metal is already on the top layer has nowhere to go and cannot jump. Jumps cost no area but use limited upper-layer slots.
• Diode adds a small device at the gate that drains the charge. It always works, but costs area.

Click a net to cycle its fix (top-layer nets only offer none / diode). Fix every net, keep jumps within their slots and diode area within budget - so jump the lower-layer nets whose diode would cost the most, and diode the rest (and the top-layer ones). Then Submit design.