fix: restore coding history and quota feedback

src/pages/Chat/CodingConversationTimeline.tsx

@@ -1265,6 +1265,19 @@ function processItemIsFailed(item: ProcessItem): boolean {
   return item.kind === 'notice' && item.node.level === 'error';
 }
 
+function persistedProviderFailureMessage(items: ProcessItem[]): string | undefined {
+  for (let index = items.length - 1; index >= 0; index -= 1) {
+    const item = items[index];
+    if (item?.kind === 'notice'
+      && item.node.level === 'error'
+      && (item.node.code === 'CODING_PROVIDER_AUTH_REQUIRED'
+        || item.node.code === 'CODING_PROVIDER_QUOTA_EXHAUSTED')) {
+      return item.node.message;
+    }
+  }
+  return undefined;
+}
+
 function processGroupIsFailed(
   items: ProcessItem[],
   run: ConversationRunState,
@@ -1326,10 +1339,13 @@ const ProcessGroup = memo(function ProcessGroup({
       ? runningDurationLabel(run, now)
       : settledDurationLabel(run)
     : null;
+  const failureMessage = failed
+    ? (latest ? run.error?.message : undefined) ?? persistedProviderFailureMessage(items)
+    : undefined;
   const summary = active
     ? `处理中${duration ? ` ${duration}` : ''}`
     : failed
-      ? `处理失败${duration ? ` · ${duration}` : ''}`
+      ? `${failureMessage ?? '处理失败'}${duration ? ` · ${duration}` : ''}`
       : `已处理${duration ? ` ${duration}` : ''}`;
 
   return (
@@ -1491,11 +1507,33 @@ export const CodingConversationTimeline = memo(function CodingConversationTimeli
   const nodes = useCodingConversationStore(selectNodes);
   const run = useCodingConversationStore(selectRun);
   const [visibleLimit, setVisibleLimit] = useState(INITIAL_WINDOW);
+  const scrollRef = useRef<HTMLDivElement | null>(null);
+  const stickToBottomRef = useRef(true);
+  const prependAnchorRef = useRef<{ scrollHeight: number; scrollTop: number } | null>(null);
   const windowStart = Math.max(0, nodes.length - visibleLimit);
   const visibleNodes = nodes.slice(windowStart);
   const turns = useMemo(() => timelineTurns(visibleNodes), [visibleNodes]);
-  const scrollRef = useRef<HTMLDivElement | null>(null);
-  const stickToBottomRef = useRef(true);
+
+  const loadEarlier = useCallback(() => {
+    if (windowStart === 0 || prependAnchorRef.current) return;
+    const element = scrollRef.current;
+    if (!element) return;
+    prependAnchorRef.current = {
+      scrollHeight: element.scrollHeight,
+      scrollTop: element.scrollTop,
+    };
+    stickToBottomRef.current = false;
+    setVisibleLimit((current) => Math.min(nodes.length, current + WINDOW_STEP));
+  }, [nodes.length, windowStart]);
+
+  useLayoutEffect(() => {
+    const anchor = prependAnchorRef.current;
+    if (!anchor) return;
+    prependAnchorRef.current = null;
+    const element = scrollRef.current;
+    if (!element) return;
+    element.scrollTop = anchor.scrollTop + (element.scrollHeight - anchor.scrollHeight);
+  }, [visibleLimit]);
 
   useLayoutEffect(() => {
     if (!stickToBottomRef.current) return;
@@ -1513,6 +1551,7 @@ export const CodingConversationTimeline = memo(function CodingConversationTimeli
       onScroll={(event) => {
         const element = event.currentTarget;
         stickToBottomRef.current = element.scrollHeight - element.scrollTop - element.clientHeight < 64;
+        if (element.scrollTop <= 48) loadEarlier();
       }}
     >
       <div className="mx-auto flex w-full max-w-[50rem] flex-col gap-8">
@@ -1521,7 +1560,7 @@ export const CodingConversationTimeline = memo(function CodingConversationTimeli
             type="button"
             variant="ghost"
             className="mx-auto min-h-9 rounded-lg px-4 text-xs transition-transform duration-150 ease-out active:scale-[0.96]"
-            onClick={() => setVisibleLimit((current) => current + WINDOW_STEP)}
+            onClick={loadEarlier}
           >
             加载更早内容
           </Button>