refactor(mp): 统一空状态为 EmptyState 组件 + 清理旧 Tab CSS

- 4 个页面的内联空状态替换为共享 EmptyState 组件
  (messages / action-inbox / pkg-health/alerts / mall)
- 清理 10 个页面的旧 Tab CSS（迁移到 SegmentTabs 后不再需要）
- 清理 elder-mode 中已删除的 mall-empty-state 引用

apps/miniprogram/src/pages/pkg-health/alerts/index.scss

@@ -105,34 +105,3 @@
   color: $tx;
   line-height: 1.5;
 }
-
-.alerts-empty {
-  display: flex;
-  flex-direction: column;
-  align-items: center;
-  justify-content: center;
-  padding: 120px 0;
-}
-
-.alerts-empty-text {
-  font-size: var(--tk-font-num);
-  color: var(--tk-text-secondary);
-  margin-bottom: 16px;
-}
-
-.alerts-empty-hint {
-  font-size: var(--tk-font-h1);
-  color: var(--tk-text-secondary);
-}
-
-.alerts-empty-action {
-  margin-top: 24px;
-  padding: 16px 48px;
-  background: $pri;
-  border-radius: $r-pill;
-}
-
-.alerts-empty-action-text {
-  color: $card;
-  font-size: var(--tk-font-body-lg);
-}

apps/miniprogram/src/pages/pkg-health/alerts/index.tsx

@@ -6,6 +6,7 @@ import { listPatientAlerts, type Alert } from '@/services/alert';
 import { useAuthStore } from '@/stores/auth';
 import Loading from '@/components/Loading';
 import ErrorState from '@/components/ErrorState';
+import EmptyState from '@/components/EmptyState';
 import SegmentTabs from '@/components/SegmentTabs';
 import { useElderClass } from '../../../hooks/useElderClass';
 import './index.scss';
@@ -98,7 +99,7 @@ export default function PatientAlerts() {
       <SegmentTabs tabs={STATUS_TABS} activeKey={status} onChange={handleTabChange} variant="pill" />
 
       {alerts.length === 0 && !loading ? (
-        <ErrorState text='暂无告警记录' hint='您的各项指标正常' />
+        <EmptyState text='暂无告警记录' hint='您的各项指标正常' />
       ) : (
         <View className='alerts-list'>
           {alerts.map((item) => {

apps/miniprogram/src/pages/pkg-health/trend/index.scss

@@ -45,29 +45,6 @@
   padding: 0 32px 28px;
 }
 
-.trange-tab {
-  padding: 12px 32px;
-  border-radius: $r-pill;
-  background: $card;
-  box-shadow: $shadow-sm;
-  transition: all 0.2s;
-}
-
-.trange-tab-active {
-  background: $pri;
-  box-shadow: $shadow-md;
-}
-
-.trange-tab-text {
-  font-size: var(--tk-font-h2);
-  color: $tx2;
-  font-weight: 500;
-}
-
-.trange-tab-text-active {
-  color: $white;
-}
-
 /* ── chart card ── */
 .trend-chart-card {
   margin: 0 24px 20px;