Revert "chore: remove all trend indicators from StatCards"

This reverts commit f258531964.

src/components/views/EfficiencyView.tsx

@@ -60,6 +60,7 @@ export function EfficiencyView() {
           value="~4.2 小时"
           subValue="主要由预约时限测算出的无效排队节省时间"
           icon={Clock}
+          trend={-42}
         />
         <StatCard
           title="平均承载饱和度 (预估)"

src/components/views/OverallView.tsx

@@ -51,12 +51,14 @@ export function OverallView() {
           value="65 单"
           subValue="嘉锦与嘉燃双核驱动，占据主流"
           icon={Calendar}
+          trend={-47}
         />
         <StatCard
           title="现阶段活跃运营站点"
           value="8 个"
           subValue="覆盖嘉燃、嘉锦、嘉燃经开、如皋、桐乡、花桥、常熟、嘉善"
           icon={MapPin}
+          trend={14}
         />
         <StatCard
           title="近期活跃司机数量"

src/components/views/UsersView.tsx

@@ -46,6 +46,7 @@ export function UsersView() {
           value="59 %"
           subValue="公司自营与核心车队"
           icon={Users}
+          trend={-36}
         />
         <StatCard
           title="近期最佳外拓来源区"