fix(canvas3d): retry transient poll failures before fail state

app/canvas/[id]/model3d/page.tsx

@@ -850,9 +850,21 @@ export default function CanvasModel3DPage() {
   );
 
   const pollAttemptsRef = useRef(0);
+  const pollErrorCountRef = useRef(0);
   const multiViewSlotsRef = useRef<MultiViewSlot[]>([]);
   const batchImageSlotsRef = useRef<MultiViewSlot[]>([]);
 
+  const MAX_RETRYABLE_TASK_POLL_FAILURES = 12;
+
+  const isRetryableTaskPollFailure = (message: string) => {
+    const normalized = String(message || "").toLowerCase();
+    return (
+      /http[^0-9]*5\d\d/.test(normalized) ||
+      normalized.includes("超时") ||
+      normalized.includes("timeout")
+    );
+  };
+
   // Fetch site settings for Logo
   const { data: siteSettingsData } = useSWR(
     "/api/site-settings?scope=branding",
@@ -1434,6 +1446,33 @@ export default function CanvasModel3DPage() {
             });
       if (!result.success || !result.data) {
         const failMessage = result.error || "任务查询失败";
+
+        if (isRetryableTaskPollFailure(failMessage)) {
+          pollErrorCountRef.current += 1;
+          if (pollErrorCountRef.current === 1) {
+            console.warn("[Model3DPage] 任务查询临时异常，继续重试", {
+              taskId: currentTask.taskId,
+              provider: currentTask.provider,
+              error: failMessage,
+              attempt: pollAttemptsRef.current,
+            });
+            toast.info(`任务查询异常，正在重试...`);
+          }
+
+          if (pollErrorCountRef.current >= MAX_RETRYABLE_TASK_POLL_FAILURES) {
+            const failedRecord: TaskRecord = {
+              ...currentTask,
+              status: "failed",
+              error: `${failMessage}（重试仍异常）`,
+            };
+            setCurrentTask(failedRecord);
+            upsertTaskHistory(failedRecord);
+          }
+
+          return;
+        }
+
+        pollErrorCountRef.current = 0;
         const failedRecord: TaskRecord = {
           ...currentTask,
           status: "failed",
@@ -1479,6 +1518,8 @@ export default function CanvasModel3DPage() {
         error:
           status === "failed" ? result.data.errorMessage || "任务失败" : null,
       };
+
+      pollErrorCountRef.current = 0;
       if (taskRecordChanged(currentTask, nextRecord)) {
         setCurrentTask(nextRecord);
         upsertTaskHistory(nextRecord);