fix(usage): Claude 流式合并 message_start/delta usage，前端移动端缓存 token 合并展示

- Claude provider state 在 message_start 记录基础 usage，message_delta 合并 output_tokens
- 前端 UsageRecordsTable 移动端缓存列改为 cache_creation + cache_read 合计展示

frontend/src/features/usage/components/UsageRecordsTable.vue

@@ -569,7 +569,7 @@
                 <span>{{ formatTokens(record.output_tokens || 0) }}</span>
               </div>
               <div class="flex items-center gap-1 text-muted-foreground">
-                <span :class="hasPositiveTokens(record.cache_read_input_tokens) ? 'text-foreground/70' : ''">{{ formatOptionalTokens(record.cache_read_input_tokens) }}</span>
+                <span :class="hasPositiveTokens(getRecordCacheTokens(record)) ? 'text-foreground/70' : ''">{{ formatOptionalTokens(getRecordCacheTokens(record)) }}</span>
                 <span>/</span>
                 <span>-</span>
               </div>
@@ -689,7 +689,7 @@ import {
 import { RefreshCcw, Search } from 'lucide-vue-next'
 import { formatTokens, formatCurrency } from '@/utils/format'
 import { formatDateTime } from '../composables'
-import { getEffectiveInputTokens } from '../token-normalization'
+import { getCacheCreationTokens, getEffectiveInputTokens } from '../token-normalization'
 import {
   formatUsageStreamLabel,
   isUsageRecordFailed,
@@ -825,6 +825,10 @@ function getRecordEffectiveInputTokens(record: UsageRecord): number {
   return getEffectiveInputTokens(record)
 }
 
+function getRecordCacheTokens(record: UsageRecord): number {
+  return getCacheCreationTokens(record) + (record.cache_read_input_tokens || 0)
+}
+
 function hasPositiveTokens(value: number | null | undefined): boolean {
   return typeof value === 'number' && Number.isFinite(value) && value > 0
 }