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

Issue: #451
User-Visible: yes

src/live-interaction-runtime.ts

@@ -0,0 +1,46 @@
+import {
+  commitHouseplanViewport, disposeHouseplanViewport, scheduleHouseplanViewport,
+} from './live-viewport';
+import { resetHouseplanHover, syncHouseplanHover } from './live-hover';
+import {
+  classifyHassRenderChange, type HassRenderDependencies,
+} from './render-invalidation';
+
+/** Lazily loaded DOM-only fast paths; the card keeps a full-render fallback. */
+export class LiveRuntime {
+  private deferredHass = false;
+  public constructor(private readonly host: any) {}
+  public hass(
+    before: any, after: any, dependencies: HassRenderDependencies | null, intake: () => void,
+  ): boolean {
+    const change = classifyHassRenderChange(before, after, dependencies);
+    const defer = change === 'state' && this.active();
+    if (defer) this.deferredHass = true;
+    this.host._renderLife.observe(before, after, dependencies, intake);
+    return change !== 'none' && !defer;
+  }
+  public clear(): void { this.deferredHass = false; }
+  public take(): boolean {
+    const pending = this.deferredHass;
+    this.deferredHass = false;
+    return pending;
+  }
+  public viewport(): void { scheduleHouseplanViewport(this.host); }
+  public hover(): void { syncHouseplanHover(this.host); }
+  public active(): boolean {
+    const host = this.host;
+    return host._pointers.size > 0 || host._cameraTransition.active || !!host._deviceDrag
+      || !!host._physicalDrag || !!host._physicalRotate || !!host._decorMove
+      || !!host._decorDraft || !!host._dtDrag || !!host._bdDrag || !!host._opDrag
+      || !!host._resize?.dragging;
+  }
+  public commit(): void {
+    commitHouseplanViewport(this.host);
+    resetHouseplanHover(this.host);
+    syncHouseplanHover(this.host);
+  }
+  public dispose(): void {
+    disposeHouseplanViewport(this.host);
+    resetHouseplanHover(this.host);
+  }
+}