drc Directory Reference

Files
	connectivity.hpp
	Copper connectivity with KiCad's semantics, shared by the DRC (unconnected/dangling checks) and the router (which pads are already joined).
	copper.hpp
	Copper items with exact shapes, built from the board model, for DRC and routing obstacles.
	drc.hpp
	Design-rule checker equivalent to KiCad's for routing-relevant rules (design doc 03 §6).
	refill.hpp
	Zone refill in the engine (doc 05 §36): the fills KiCad 10's zone filler would draw for the board's current copper, so connectivity can be judged as kicad-cli pcb drc --refill-zones judges it.
	rule_engine.hpp
	Resolves KiCad constraints for pairs of copper items (design doc 03 §6): net-class clearances, local pad overrides, board minimums and custom .kicad_dru rules with their conditions.
	rule_geometry.hpp
	Positional custom-rule predicates.