fix(threads): 忽略流取消导致的错误提示

识别 cancelled/canceled/abort 等取消信号。\n在流式请求被主动停止或中断时不再弹出错误 toast，减少误报。

frontend/src/components/workspace/workspace-header.tsx

@@ -43,7 +43,7 @@ export function WorkspaceHeader({ className }: { className?: string }) {
             ) : (
               <div className="text-primary ml-2 cursor-default font-serif">
                 {/* TODO: 测试标识 */}
-                XClaw <span className="text-sm text-[#000000c5]">v3.2.3</span>
+                XClaw <span className="text-sm text-[#000000c5]">v3.2.4</span>
               </div>
             )}
             <SidebarTrigger />

frontend/src/core/threads/hooks.ts

@@ -49,6 +49,12 @@ export type LegacyThreadStreamOptions = {
 const STREAM_ERROR_FALLBACK_MESSAGE = "Request failed.";
 const STREAM_ERROR_TOAST_MESSAGE = "出现了某些错误。";
 const STREAM_ERROR_TOAST_DEDUPE_WINDOW_MS = 2000;
+const STREAM_CANCEL_PATTERNS = [
+  /\bcancellederror\b/i,
+  /\bcancelled\b/i,
+  /\bcanceled\b/i,
+  /\babort(?:ed|error)?\b/i,
+];
 
 function readMessageCandidate(value: unknown): string | null {
   if (typeof value === "string" && value.trim()) {
@@ -116,6 +122,21 @@ function getStreamErrorMessage(error: unknown): string {
   return STREAM_ERROR_FALLBACK_MESSAGE;
 }
 
+function isStreamCancellation(error: unknown, message: string): boolean {
+  const direct =
+    typeof error === "object" &&
+    error !== null &&
+    "name" in error &&
+    typeof Reflect.get(error, "name") === "string"
+      ? String(Reflect.get(error, "name"))
+      : "";
+
+  const candidates = [message, direct];
+  return candidates.some((value) =>
+    STREAM_CANCEL_PATTERNS.some((pattern) => pattern.test(value)),
+  );
+}
+
 function normalizeThreadId(
   value: string | null | undefined,
 ): string | undefined {
@@ -234,6 +255,11 @@ export function useThreadStream({
 
   const showStreamErrorToast = useCallback((error: unknown) => {
     const message = getStreamErrorMessage(error);
+    if (isStreamCancellation(error, message)) {
+      // Cancellation is expected when user presses "Stop" or stream disconnects.
+      console.info("[useThreadStream] stream cancelled:", message);
+      return;
+    }
     const now = Date.now();
     const lastToast = lastErrorToastRef.current;
     if (