feat(control): grid snap, NPC context actions, and overlay dim fix

Re-enable users-branch UI, snap session tokens to square/hex grid from the control preview, refine inactive/open-info NPC menus, block marker actions while an effect brush is active, and dim materials/NPC overlays only when they are open.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/shared/materials/MaterialOverlay.module.css

@@ -38,9 +38,11 @@
   cursor: zoom-out;
 }
 
+/** Затемнение всего родителя (превью пульта / экран презентации); только при открытом материале/NPC. */
 .dim {
   position: absolute;
   inset: 0;
+  z-index: 39;
   background: rgba(0, 0, 0, 0.62);
   pointer-events: none;
 }