fix(canvas): stop the layer-order render loop during region drag

src/renderer/src/features/workspace/canvasStacking.ts

@@ -1,15 +1,15 @@
 import type { CameraState, SessionBounds } from "../../../../shared/contracts";
 
 export function reconcileCanvasLayerOrder(
-  current: readonly string[],
+  current: string[],
   active: readonly string[]
 ): string[] {
   const activeSet = new Set(active);
   const next = current.filter((id, index) => activeSet.has(id) && current.indexOf(id) === index);
   for (const id of active) {
     if (!next.includes(id)) next.push(id);
   }
-  return next;
+  return next.length === current.length && next.every((id, index) => id === current[index]) ? current : next;
 }
 
 export function bringCanvasLayerToFront(current: readonly string[], id: string): string[] {

tests/canvas-stacking.test.mjs

@@ -32,6 +32,12 @@ test("layer reconciliation keeps user order and appends only new live windows",
   );
 });
 
+test("an unchanged layer order reconciles to the same array", () => {
+  const order = ["browser", "terminal:a", "note:n"];
+  assert.equal(reconcileCanvasLayerOrder(order, ["note:n", "terminal:a", "browser"]), order);
+  assert.notEqual(reconcileCanvasLayerOrder(order, ["terminal:a", "browser"]), order);
+});
+
 test("the native Browser surface is hidden only under a higher overlapping layer", () => {
   const map = new Map([
     ["browser", bounds(0, 0)],