fix(frontend): 修复UI改进分支中的关键问题

- 修复RedeemView订阅刷新失败导致流程中断的问题
  将订阅刷新隔离到独立try/catch，失败时仅显示警告
- 修复DataTable resize事件监听器泄漏问题
  确保添加和移除使用同一个回调引用
- 修复订阅状态缓存导致强制刷新失效的问题
  force=true时绕过activePromise缓存，clear()清空缓存
- 修复图表主题切换后颜色不更新的问题
  添加图表ref并在主题切换时调用update()方法

frontend/src/views/user/DashboardView.vue

@@ -336,6 +336,7 @@
                 <div class="h-48 w-48">
                   <Doughnut
                     v-if="modelChartData"
+                    ref="modelChartRef"
                     :data="modelChartData"
                     :options="doughnutOptions"
                   />
@@ -400,7 +401,12 @@
                 {{ t('dashboard.tokenUsageTrend') }}
               </h3>
               <div class="h-48">
-                <Line v-if="trendChartData" :data="trendChartData" :options="lineOptions" />
+                <Line
+                  v-if="trendChartData"
+                  ref="trendChartRef"
+                  :data="trendChartData"
+                  :options="lineOptions"
+                />
                 <div
                   v-else
                   class="flex h-full items-center justify-center text-sm text-gray-500 dark:text-gray-400"
@@ -657,7 +663,7 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed, onMounted, watch } from 'vue'
+import { ref, computed, onMounted, watch, nextTick } from 'vue'
 import { useRouter } from 'vue-router'
 import { useI18n } from 'vue-i18n'
 import { useAuthStore } from '@/stores/auth'
@@ -710,9 +716,13 @@ const loading = ref(false)
 const loadingUsage = ref(false)
 const loadingCharts = ref(false)
 
+type ChartComponentRef = { chart?: ChartJS }
+
 // Chart data
 const trendData = ref<TrendDataPoint[]>([])
 const modelStats = ref<ModelStat[]>([])
+const modelChartRef = ref<ChartComponentRef | null>(null)
+const trendChartRef = ref<ChartComponentRef | null>(null)
 
 // Recent usage
 const recentUsage = ref<UsageLog[]>([])
@@ -1036,7 +1046,10 @@ onMounted(async () => {
 
 // Watch for dark mode changes
 watch(isDarkMode, () => {
-  // Force chart re-render on theme change
+  nextTick(() => {
+    modelChartRef.value?.chart?.update()
+    trendChartRef.value?.chart?.update()
+  })
 })
 </script>
 

frontend/src/views/user/RedeemView.vue

@@ -548,7 +548,12 @@ const handleRedeem = async () => {
 
     // If subscription type, immediately refresh subscription status
     if (result.type === 'subscription') {
-      await subscriptionStore.fetchActiveSubscriptions(true) // force refresh
+      try {
+        await subscriptionStore.fetchActiveSubscriptions(true) // force refresh
+      } catch (error) {
+        console.error('Failed to refresh subscriptions after redeem:', error)
+        appStore.showWarning(t('redeem.subscriptionRefreshFailed'))
+      }
     }
 
     // Clear the input