feat(sts-like-viewer): batch inventory item movement

Wrap item removal and placement in a batch to prevent multiple
reactive updates when moving items between inventories.

packages/sts-like-viewer/src/state/inventory.ts

@@ -10,6 +10,7 @@ import {
   Transform2D,
   validatePlacement,
 } from "boardgame-core/samples/slay-the-spire-like";
+import { batch } from "@preact/signals-core";
 
 function genId() {
   return Math.random().toString(16).slice(-8);
@@ -62,6 +63,7 @@ export function moveItem(
   const validation = validatePlacement(removed, item.shape, newTransform);
   if (!validation.valid) return false;
 
+  batch(() => {
     from.produce((inv) => {
       removeItemFromGrid(inv, itemId);
     });
@@ -71,6 +73,7 @@ export function moveItem(
         transform: newTransform,
       });
     });
+  });
 
   return true;
 }