fix(heal): eliminate brush cursor mouse lag and stutter in desktop STUDIO by bypassing React reconciliation on pointermove

docker/frontend/src/engine/inpaint.ts

@@ -75,15 +75,21 @@ async function hasDevice(): Promise<boolean> {
   }
 }
 
+let isWebGPUActive = false;
+
 // WebGPU on the main thread: asynchronous and GPU-bound.
 async function openSession(ort: typeof Ort): Promise<Ort.InferenceSession> {
   if (await hasDevice()) {
     try {
       const gpu = await ort.InferenceSession.create(MODEL_URL, { executionProviders: ['webgpu'] });
-      if (await warmsUp(ort, gpu)) return gpu;
+      if (await warmsUp(ort, gpu)) {
+        isWebGPUActive = true;
+        return gpu;
+      }
       await gpu.release();
     } catch {}
   }
+  isWebGPUActive = false;
   return ort.InferenceSession.create(MODEL_URL, {
     executionProviders: ['wasm'],
     enableCpuMemArena: false,