refactor: 统一分页组件和UI优化

- 使用公共Pagination组件统一各页面的分页逻辑
- 优化exceptions页面异常列表展示
- 简化settings/rules页面规则管理
- 后端tasks.py增加分页参数支持

frontend/app/(dashboard)/tasks/[id]/mapping/page.tsx

@@ -439,12 +439,12 @@ export default function MappingPage() {
     [toast]
   );
 
-  // 确认并进入下一步
+  // 确认并进入下一步 - 跳转到对账结果页面
   const handleConfirmAndNext = useCallback(async () => {
     try {
       setLoading(true);
       toast.success("字段映射已确认，正在进入对账...");
-      router.push(`/tasks/${taskId}/reconciliation`);
+      router.push(`/tasks/${taskId}/result`);
     } catch {
       toast.error("操作失败");
     } finally {
@@ -475,7 +475,7 @@ export default function MappingPage() {
         className="flex items-center justify-between"
       >
         <div className="flex items-center gap-4">
-          <Button variant="ghost" size="icon" onClick={() => router.push("/dashboard")} className="hover:bg-muted">
+          <Button variant="ghost" size="icon" onClick={() => router.push("/tasks")} className="hover:bg-muted">
             <ArrowLeft className="h-4 w-4" />
           </Button>
           <div>

frontend/app/(dashboard)/tasks/page.tsx

@@ -82,14 +82,13 @@ export default function TasksPage() {
 
   useEffect(() => {
     loadTasks();
-  }, [loadTasks]);
+  }, [loadTasks, page, pageSize, selectedPeriod]);
 
   function onPageChange(newPage: number, newPageSize: number) {
     setPage(newPage);
     if (newPageSize !== pageSize) {
       setPageSize(newPageSize);
     }
-    loadTasks();
   }
 
   const getMatchRate = (task: Task) => {
@@ -99,7 +98,7 @@ export default function TasksPage() {
   };
 
   return (
-    <div className="min-h-full p-6 lg:p-8 max-w-6xl mx-auto">
+    <div className="min-h-full p-6 lg:p-8 max-w-7xl mx-auto space-y-6">
       {/* Header */}
       <motion.div 
         initial={{ opacity: 0, y: -8 }}