fix: 修复日期范围选择器时区和性能问题

- 修复时区问题：使用本地时区格式化日期，避免 toISOString() 导致的日期偏移
- 优化日期范围选择器性能：使用 untrack 避免循环更新
- 统一日期格式化方法：在 utils.ts 中添加 formatLocalDate 工具函数
- 修复分页逻辑：优化页码计算和显示
- 更新相关页面：bills 和 analysis 页面使用统一的日期格式化方法

web/src/lib/components/analysis/DailyTrendChart.svelte

@@ -11,6 +11,7 @@
   import { Button } from '$lib/components/ui/button';
   import type { BillRecord } from '$lib/api';
   import { pieColors } from '$lib/constants/chart';
+  import { formatLocalDate } from '$lib/utils';
   import BillRecordsTable from './BillRecordsTable.svelte';
 
   interface Props {
@@ -96,7 +97,7 @@
     const day = d.getDay();
     const diff = d.getDate() - day + (day === 0 ? -6 : 1); // 调整到周一
     d.setDate(diff);
-    return d.toISOString().split('T')[0];
+    return formatLocalDate(d);
   }
   
   // 获取月份标识
@@ -526,7 +527,7 @@
     
     // 点击图表任意位置都触发，选择最近的日期
     const clickedDate = data[closestIdx].date;
-    const dateStr = clickedDate.toISOString().split('T')[0];
+    const dateStr = formatLocalDate(clickedDate);
     
     // 找出当天的所有支出记录
     selectedDate = clickedDate;

web/src/lib/components/ui/date-range-picker/date-range-picker.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import { untrack } from 'svelte';
   import { CalendarDate, type DateValue } from "@internationalized/date";
   import CalendarIcon from "@lucide/svelte/icons/calendar";
   import * as Popover from "$lib/components/ui/popover";
@@ -29,12 +30,45 @@
     return `${date.year}-${String(date.month).padStart(2, '0')}-${String(date.day).padStart(2, '0')}`;
   }
 
-  // 内部日期范围状态，使用 $derived 响应 props 变化
+  // 内部日期范围状态
-  let value: DateRange = $derived({
+  let value: DateRange = $state({
     start: parseDate(startDate),
     end: parseDate(endDate)
   });
 
+  // 当 startDate 或 endDate 从外部变化时，同步更新 value
+  $effect(() => {
+    const newStart = parseDate(startDate);
+    const newEnd = parseDate(endDate);
+    
+    // 检查值是否真的变化了
+    const currentStartStr = untrack(() => value.start ? formatDate(value.start) : '');
+    const currentEndStr = untrack(() => value.end ? formatDate(value.end) : '');
+    
+    if (currentStartStr !== startDate || currentEndStr !== endDate) {
+      value = {
+        start: newStart,
+        end: newEnd
+      };
+    }
+  });
+
+  // 当 value 变化时（用户通过日历选择），更新绑定的 startDate 和 endDate
+  $effect(() => {
+    const newStartDate = value.start ? formatDate(value.start) : '';
+    const newEndDate = value.end ? formatDate(value.end) : '';
+    
+    // 检查是否与当前值不同，避免循环更新
+    if (newStartDate !== untrack(() => startDate) || newEndDate !== untrack(() => endDate)) {
+      startDate = newStartDate;
+      endDate = newEndDate;
+      // 调用回调函数（只在有完整日期范围时）
+      if (onchange && value.start && value.end) {
+        onchange(newStartDate, newEndDate);
+      }
+    }
+  });
+
   // 格式化显示文本
   let displayText = $derived(() => {
     if (value.start && value.end) {
@@ -45,13 +79,6 @@
     }
     return "选择日期范围";
   });
-
-  // 当日期变化时通知父组件
-  function handleValueChange(newValue: DateRange) {
-    if (newValue.start && newValue.end && onchange) {
-      onchange(formatDate(newValue.start), formatDate(newValue.end));
-    }
-  }
 </script>
 
 <Popover.Root>
@@ -73,8 +100,7 @@
   </Popover.Trigger>
   <Popover.Content class="w-auto p-0" align="start">
     <RangeCalendar
-      {value}
+      bind:value
-      onValueChange={handleValueChange}
       numberOfMonths={2}
       locale="zh-CN"
       weekStartsOn={1}

web/src/lib/utils.ts

@@ -5,6 +5,17 @@ export function cn(...inputs: ClassValue[]) {
 	return twMerge(clsx(inputs));
 }
 
+/**
+ * 使用本地时区格式化日期为 YYYY-MM-DD 格式
+ * 避免使用 toISOString() 导致的时区转换问题
+ */
+export function formatLocalDate(date: Date): string {
+	const y = date.getFullYear();
+	const m = String(date.getMonth() + 1).padStart(2, '0');
+	const d = String(date.getDate()).padStart(2, '0');
+	return `${y}-${m}-${d}`;
+}
+
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export type WithoutChild<T> = T extends { child?: any } ? Omit<T, "child"> : T;
 // eslint-disable-next-line @typescript-eslint/no-explicit-any

web/src/routes/analysis/+page.svelte

@@ -5,6 +5,7 @@
   import { Badge } from '$lib/components/ui/badge';
   import * as Card from '$lib/components/ui/card';
   import { DateRangePicker } from '$lib/components/ui/date-range-picker';
+  import { formatLocalDate } from '$lib/utils';
   import BarChart3 from '@lucide/svelte/icons/bar-chart-3';
   import Loader2 from '@lucide/svelte/icons/loader-2';
   import AlertCircle from '@lucide/svelte/icons/alert-circle';
@@ -41,8 +42,9 @@
     const today = new Date();
     const year = today.getFullYear();
     const month = today.getMonth();
-    const startDate = new Date(year, month, 1).toISOString().split('T')[0];
+    
-    const endDate = today.toISOString().split('T')[0];
+    const startDate = formatLocalDate(new Date(year, month, 1));
+    const endDate = formatLocalDate(today);
     return { startDate, endDate };
   }
   const defaultDates = getDefaultDates();

web/src/routes/bills/+page.svelte

@@ -8,6 +8,7 @@
   import { Label } from '$lib/components/ui/label';
   import * as Table from '$lib/components/ui/table';
   import { DateRangePicker } from '$lib/components/ui/date-range-picker';
+  import { formatLocalDate } from '$lib/utils';
   import Loader2 from '@lucide/svelte/icons/loader-2';
   import AlertCircle from '@lucide/svelte/icons/alert-circle';
   import Search from '@lucide/svelte/icons/search';
@@ -40,8 +41,9 @@
     const today = new Date();
     const year = today.getFullYear();
     const month = today.getMonth();
-    const startDate = new Date(year, month, 1).toISOString().split('T')[0];
+    
-    const endDate = today.toISOString().split('T')[0];
+    const startDate = formatLocalDate(new Date(year, month, 1));
+    const endDate = formatLocalDate(today);
     return { startDate, endDate };
   }
   const defaultDates = getDefaultDates();
@@ -221,11 +223,9 @@
           <div class="space-y-1.5 col-span-2 sm:col-span-2">
             <Label class="text-xs">日期范围</Label>
             <DateRangePicker 
-              {startDate}
+              bind:startDate
-              {endDate}
+              bind:endDate
               onchange={(start, end) => {
-                startDate = start;
-                endDate = end;
                 applyFilters();
               }}
             />
@@ -344,6 +344,9 @@
         <div class="flex items-center justify-between mt-4">
           <p class="text-sm text-muted-foreground">
             显示 {(currentPage - 1) * pageSize + 1} - {Math.min(currentPage * pageSize, totalRecords)} 条，共 {totalRecords} 条
+            {#if searchText}
+              <span class="text-muted-foreground/70">（当前页筛选后：{displayRecords.length} 条）</span>
+            {/if}
           </p>
           <div class="flex items-center gap-2">
             <Button 
@@ -356,13 +359,17 @@
               上一页
             </Button>
             <div class="flex items-center gap-1">
-              {#each Array.from({ length: Math.min(5, totalPages) }, (_, i) => {
+              {#each (() => {
-                // 计算显示的页码范围
+                // 计算显示的页码范围（最多显示5页）
-                let start = Math.max(1, currentPage - 2);
+                const maxPages = 5;
-                let end = Math.min(totalPages, start + 4);
+                let start = Math.max(1, currentPage - Math.floor(maxPages / 2));
-                start = Math.max(1, end - 4);
+                let end = Math.min(totalPages, start + maxPages - 1);
-                return start + i;
+                // 如果右侧空间不足，向左调整
-              }).filter(p => p <= totalPages) as page}
+                if (end - start < maxPages - 1) {
+                  start = Math.max(1, end - maxPages + 1);
+                }
+                return Array.from({ length: end - start + 1 }, (_, i) => start + i);
+              })() as page}
                 <Button 
                   variant={page === currentPage ? 'default' : 'outline'}
                   size="sm"