reorganized imports

src/diagram.typ

@@ -1,9 +1,7 @@
-#import "core/utils.typ": fit-canvas, set-ctx
-#import "core/renderer.typ": render
-#import "participant.typ" as participant: _par, PAR-SPECIALS
-#import "sequence.typ": _seq
 #import "core/draw/event.typ": render as evt-render
+#import "core/renderer.typ": render
 #import "core/setup.typ": setup
+#import "core/utils.typ": fit-canvas, set-ctx
 
 #let gap-render(gap) = set-ctx(ctx => {
   ctx.y -= gap.size