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/playerToken/SceneNpcTokensOverlay.tsx

@@ -43,6 +43,7 @@ function NpcSprite({
   inactive,
   onMove,
   onContextMenu,
+  snapNorm,
 }: {
   placement: SceneNpcToken;
   npc: ProjectNpc;
@@ -56,6 +57,7 @@ function NpcSprite({
   inactive: boolean;
   onMove?: (placementId: string, nx: number, ny: number) => void;
   onContextMenu?: (e: React.MouseEvent, placement: SceneNpcToken) => void;
+  snapNorm?: (nx: number, ny: number) => { nx: number; ny: number };
 }) {
   const imageUrl = useAssetUrl(npc.avatarAssetId);
   const [localPos, setLocalPos] = useState<{ nx: number; ny: number } | null>(null);
@@ -135,8 +137,11 @@ function NpcSprite({
               const drag = dragRef.current;
               if (drag?.pointerId !== e.pointerId) return;
               const p = point(e);
-              drag.lastNx = Math.max(0, Math.min(1, drag.startNx + p.x - drag.pointerNx));
-              drag.lastNy = Math.max(0, Math.min(1, drag.startNy + p.y - drag.pointerNy));
+              const rawNx = Math.max(0, Math.min(1, drag.startNx + p.x - drag.pointerNx));
+              const rawNy = Math.max(0, Math.min(1, drag.startNy + p.y - drag.pointerNy));
+              const snapped = snapNorm ? snapNorm(rawNx, rawNy) : { nx: rawNx, ny: rawNy };
+              drag.lastNx = snapped.nx;
+              drag.lastNy = snapped.ny;
               setLocalPos({ nx: drag.lastNx, ny: drag.lastNy });
               schedule(drag.lastNx, drag.lastNy);
             }
@@ -167,6 +172,7 @@ export function SceneNpcTokensOverlay({
   editable = false,
   onMove,
   onContextMenu,
+  snapNorm,
 }: {
   placements: readonly SceneNpcToken[];
   library: readonly ProjectNpc[];
@@ -177,6 +183,7 @@ export function SceneNpcTokensOverlay({
   editable?: boolean;
   onMove?: (placementId: string, nx: number, ny: number) => void;
   onContextMenu?: (e: React.MouseEvent, placement: SceneNpcToken) => void;
+  snapNorm?: (nx: number, ny: number) => { nx: number; ny: number };
 }) {
   if (!viewport) return null;
   const byId = new Map(library.map((npc) => [npc.id, npc]));
@@ -205,6 +212,7 @@ export function SceneNpcTokensOverlay({
             inactive={inactive}
             {...(onMove ? { onMove } : {})}
             {...(onContextMenu ? { onContextMenu } : {})}
+            {...(snapNorm ? { snapNorm } : {})}
           />
         );
       })}