fix: 改进瀑布流滚动和回到顶部的可靠性

- 使用 ref 避免 loadMore 依赖导致事件重复注册
- 同时监听 window 和 document 的 scroll 事件
- 降低回到顶部按钮触发阈值到 400px
- 增大触底检测距离到 300px

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/modules/mileage/MonitoringView.tsx

@@ -179,19 +179,26 @@ export default function MonitoringView() {
   }, [loadFirstPage]);
 
   // 滚动触底检测 + 回到顶部按钮
+  const loadMoreRef = useRef(loadMore);
+  loadMoreRef.current = loadMore;
+
   useEffect(() => {
     const handleScroll = () => {
-      const scrollY = window.scrollY;
-      setShowBackToTop(scrollY > 600);
+      const scrollY = window.scrollY || document.documentElement.scrollTop;
+      setShowBackToTop(scrollY > 400);
       const scrollHeight = document.documentElement.scrollHeight;
       const clientHeight = window.innerHeight;
-      if (scrollHeight - scrollY - clientHeight < 200) {
-        loadMore();
+      if (scrollHeight - scrollY - clientHeight < 300) {
+        loadMoreRef.current();
       }
     };
     window.addEventListener('scroll', handleScroll, { passive: true });
-    return () => window.removeEventListener('scroll', handleScroll);
-  }, [loadMore]);
+    document.addEventListener('scroll', handleScroll, { passive: true });
+    return () => {
+      window.removeEventListener('scroll', handleScroll);
+      document.removeEventListener('scroll', handleScroll);
+    };
+  }, []);
 
   const scrollToTop = () => {
     window.scrollTo({ top: 0, behavior: 'smooth' });