fix: keep large-plan interactions off the full render path

Issue: #451
User-Visible: yes

src/pointer-move-queue.ts

@@ -0,0 +1,48 @@
+interface QueuedMove { raf: number; run: () => void }
+
+const moveQueues = new WeakMap<object, Map<string, QueuedMove>>();
+
+/** Keep only the latest raw move of each active gesture between two frames. */
+export function queueHouseplanPointerMove(host: object, key: string, run: () => void): void {
+  let queues = moveQueues.get(host);
+  if (!queues) {
+    queues = new Map();
+    moveQueues.set(host, queues);
+  }
+  const queued = queues.get(key);
+  if (queued) {
+    queued.run = run;
+    return;
+  }
+  const entry: QueuedMove = { raf: 0, run };
+  queues.set(key, entry);
+  if (typeof requestAnimationFrame !== 'function') {
+    queues.delete(key);
+    run();
+    return;
+  }
+  entry.raf = requestAnimationFrame(() => {
+    queues!.delete(key);
+    entry.run();
+  });
+}
+
+export function flushHouseplanPointerMove(host: object, key: string): void {
+  const queues = moveQueues.get(host);
+  const queued = queues?.get(key);
+  if (!queued) return;
+  if (queued.raf && typeof cancelAnimationFrame === 'function') cancelAnimationFrame(queued.raf);
+  queues!.delete(key);
+  queued.run();
+}
+
+export function cancelHouseplanPointerMove(host: object, key?: string): void {
+  const queues = moveQueues.get(host);
+  if (!queues) return;
+  const entries = key ? [...queues].filter(([name]) => name === key) : [...queues];
+  for (const [name, queued] of entries) {
+    if (queued.raf && typeof cancelAnimationFrame === 'function') cancelAnimationFrame(queued.raf);
+    queues.delete(name);
+  }
+  if (!queues.size) moveQueues.delete(host);
+}