feat: 统计页面添加分类筛选与搜索优化

- 统计页面添加分类多选筛选功能
- 点击分类可跳转到搜索页面查看详情
- 搜索页面添加 URL 同步与自动搜索
- 提取 useCategories hook 消除重复代码
- 修复自定义分类图标显示问题
- 添加 useMemo 优化计算性能

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/styles/globals.css

@@ -1207,14 +1207,6 @@ textarea:focus-visible {
   gap: 10px;
 }
 
-.search-stat {
-  padding: 13px;
-  background: rgba(246, 248, 252, 0.82);
-  border: 1px solid rgba(148, 163, 184, 0.14);
-  display: grid;
-  gap: 6px;
-}
-
 .section-card--search .results-count {
   padding: 0 2px;
   font-weight: 600;
@@ -1591,6 +1583,18 @@ textarea:focus-visible {
   background: rgba(246, 248, 252, 0.8);
 }
 
+.stats-category-item--clickable {
+  cursor: pointer;
+  border: none;
+  width: 100%;
+  text-align: left;
+  transition: background 0.2s ease;
+}
+
+.stats-category-item--clickable:hover {
+  background: rgba(37, 99, 235, 0.1);
+}
+
 .stats-category-header {
   display: flex;
   justify-content: space-between;
@@ -1622,6 +1626,95 @@ textarea:focus-visible {
   background: linear-gradient(90deg, var(--primary), #60a5fa);
 }
 
+/* 统计页面总额显示 */
+.stats-total {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 12px 16px;
+  background: var(--card-bg);
+  border-radius: 8px;
+  margin-bottom: 12px;
+}
+
+.stats-total-label {
+  font-size: 14px;
+  color: var(--text-secondary);
+}
+
+.stats-total-amount {
+  font-size: 20px;
+  font-weight: 600;
+  color: var(--text-primary);
+}
+
+/* 分类选择chips */
+.category-chips {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+  margin-bottom: 12px;
+}
+
+.category-chip {
+  padding: 6px 12px;
+  border-radius: 16px;
+  border: 1px solid var(--border-color);
+  background: var(--card-bg);
+  color: var(--text-secondary);
+  font-size: 13px;
+  cursor: pointer;
+  transition: all 0.2s ease;
+}
+
+.category-chip:hover {
+  border-color: var(--primary);
+  color: var(--primary);
+}
+
+.category-chip.selected {
+  background: var(--primary);
+  border-color: var(--primary);
+  color: white;
+}
+
+/* 已选分类标签 */
+.selected-chips {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+  margin-bottom: 12px;
+}
+
+.selected-chip {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  padding: 4px 8px 4px 12px;
+  border-radius: 16px;
+  background: var(--primary);
+  color: white;
+  font-size: 13px;
+}
+
+.selected-chip-remove {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 18px;
+  height: 18px;
+  border-radius: 50%;
+  border: none;
+  background: rgba(255, 255, 255, 0.3);
+  color: white;
+  cursor: pointer;
+  padding: 0;
+}
+
+.selected-chip-remove:hover {
+  background: rgba(255, 255, 255, 0.5);
+}
+
 .category-item .category-name {
   white-space: nowrap;
   overflow: hidden;