ADDED: API for injecting arbitrary DRC errors/warn

Allows external tools to calculate/represent specialized DRC errors on
the board

Fixes https://gitlab.com/kicad/code/kicad/issues/21727

api/proto/board/board_commands.proto

@@ -258,6 +258,34 @@ message PadstackPresenceResponse
   repeated PadstackPresenceEntry entries = 1;
 }
 
+// DRC markers
+
+enum DrcSeverity // Since 10.0
+{
+  DRS_UNKNOWN = 0;
+  DRS_WARNING = 1;
+  DRS_ERROR = 2;
+}
+
+// Returns InjectDrcErrorResponse
+message InjectDrcError
+{
+  kiapi.common.types.DocumentSpecifier board = 1;
+
+  DrcSeverity severity = 2;
+
+  string message = 3;
+
+  kiapi.common.types.Vector2 position = 4;
+
+  repeated kiapi.common.types.KIID items = 5;
+}
+
+message InjectDrcErrorResponse
+{
+  kiapi.common.types.KIID marker = 1;
+}
+
 // PCB editor commands
 
 // returns BoardLayers