fix(producer): retry segmented capture on screenshot after a sequential stall

captureSegmentFrames races each frame through raceAgainstStall, which throws
SequentialCaptureStallError. The segmented catch only retried drawElement
capture, verification and renderer-stall errors, so a drawElement frame that
hung without the engine's frame timeout firing failed the whole render, where
the streaming path retries the same error on a fresh screenshot session.

Retry it when the plan did not already force screenshot. The failure kind is
draw_element_capture, which keeps segmenting and forces screenshot;
capture_failure would replan to plain streaming, which this catch cannot
drive. deFallbackReason stays "capture_error", the value streaming records
for a sequential stall.

— Via

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

packages/producer/src/services/renderOrchestrator.segmentedDeRetry.test.ts

@@ -190,6 +190,14 @@ function render(resumeSegments = false): Promise<void> {
   return executeRenderJob(job, root, join(root, "output.mp4"));
 }
 
+function sequentialStall(): Error {
+  const err = new Error(
+    "[Render] Sequential drawElement capture stalled: no frame progress for 1000ms (stuck at frame 640/1200).",
+  );
+  err.name = "SequentialCaptureStallError";
+  return err;
+}
+
 function stalledRenderer(): Error {
   const err = new Error("drawElement frame exceeded 5000ms (renderer stopped scheduling)");
   err.name = "DeFrameTimeoutError";
@@ -200,6 +208,7 @@ it.each([
   ["a suspect small frame", () => new DrawElementCaptureError(640, "suspect small frame")],
   ["no cached paint record", () => new DrawElementCaptureError(640, "No cached paint record")],
   ["a stalled renderer", stalledRenderer],
+  ["a sequential capture stall", sequentialStall],
   [
     "a failed self-verification",
     () => new DrawElementVerificationError("drawElement PSNR too low", { kind: "psnr" }),

packages/producer/src/services/renderOrchestrator.ts

@@ -4741,8 +4741,13 @@ async function executeRenderPipeline(input: {
         } catch (err) {
           const isVerifyError = isDrawElementVerificationError(err);
           const isDeStall = isDeRendererStallError(err);
+          const isUnforcedSequentialStall =
+            isSequentialCaptureStallError(err) && !capturePlan.forceScreenshot;
           if (
-            (!isVerifyError && !isDrawElementCaptureError(err) && !isDeStall) ||
+            (!isVerifyError &&
+              !isDrawElementCaptureError(err) &&
+              !isDeStall &&
+              !isUnforcedSequentialStall) ||
             err instanceof RenderCancelledError ||
             executionSignal?.aborted === true
           ) {
@@ -4759,7 +4764,9 @@ async function executeRenderPipeline(input: {
           deFallbackFrameIndex = t.frameIndex;
           deFallbackThresholdDb = t.thresholdDb;
           log.warn(
-            "[Render] drawElement capture failed on the segmented path; re-rendering via screenshot",
+            isUnforcedSequentialStall
+              ? "[Render] segmented capture stalled; retrying on a fresh screenshot session"
+              : "[Render] drawElement capture failed on the segmented path; re-rendering via screenshot",
             {
               error: err instanceof Error ? err.message : String(err),
             },