fix(producer): address review nits on worker-pool crash recovery

- Reword the dead-marking comments in both onWorkerError handlers: the
  flag is set before rejecting and before draining the queue, not
  "before anything else" (current/busy are cleared first).
- Rename the shader pool's all-slots-die test to match the png pool's
  equivalent; the size-2 fixture crashes every worker, so there are no
  surviving workers serving.

Author: calcarazgre646

packages/producer/src/services/pngDecodeBlitWorkerPool.ts

@@ -365,9 +365,9 @@ export async function createPngDecodeBlitWorkerPool(
     const task = slot.current;
     slot.current = null;
     slot.busy = false;
-    // Mark dead BEFORE anything else so this slot is excluded from future
-    // dispatch; postMessage to its terminated worker would be a silent no-op
-    // and any task routed here would hang.
+    // Mark dead before rejecting and before draining the queue so this slot is
+    // excluded from future dispatch; postMessage to its terminated worker would
+    // be a silent no-op and any task routed here would hang.
     slot.dead = true;
     if (task) {
       task.reject(

packages/producer/src/services/shaderTransitionWorkerPool.test.ts

@@ -374,9 +374,9 @@ describe("ShaderTransitionWorkerPool", () => {
       expect(await queued).toBe("rejected");
     });
 
-    it("keeps serving on surviving workers after one slot dies", async () => {
-      // Size 2: both slots run the crashing fixture, so a real blend can't be
-      // asserted here, but the pool must not wedge — every run settles.
+    it("never wedges the pool when all slots die", async () => {
+      // Size 2: both slots run the crashing fixture, so there are no surviving
+      // workers; the pool must still never wedge — every run settles.
       const pool = await makeCrashPool(2);
       const results = await Promise.all([
         settledWithin(pool.run(blendReq())),

packages/producer/src/services/shaderTransitionWorkerPool.ts

@@ -308,9 +308,10 @@ export async function createShaderTransitionWorkerPool(
     const task = slot.current;
     slot.current = null;
     slot.busy = false;
-    // Mark dead BEFORE anything else: this slot's worker can no longer accept
-    // a dispatch (postMessage would be a silent no-op), so it must be excluded
-    // from future slot selection or a later task would hang on it.
+    // Mark dead before rejecting and before draining the queue: this slot's
+    // worker can no longer accept a dispatch (postMessage would be a silent
+    // no-op), so it must be excluded from future slot selection or a later
+    // task would hang on it.
     slot.dead = true;
     if (task) {
       // The in-flight task's buffers were transferred to the worker. They're