feat(admin): 将用户管理的用量统计改为全量累计口径 (#314)

- 新增按用户 ID 批量汇总 usage 的后端查询
- 在 /api/admin/users 中返回 request_count 和 total_tokens
- 移除用户管理页面额外的 usage 聚合请求
- 为管理端用户列表补充累计统计回归测试

crates/aether-data-contracts/src/repository/usage/mod.rs

@@ -9,10 +9,10 @@ pub use types::{
     StoredUsageDashboardDailyBreakdownRow, StoredUsageDashboardProviderCount,
     StoredUsageDashboardSummary, StoredUsageErrorDistributionRow, StoredUsageLeaderboardSummary,
     StoredUsagePerformancePercentilesRow, StoredUsageSettledCostSummary,
-    StoredUsageTimeSeriesBucket, UpsertUsageRecord, UsageAuditAggregationGroupBy,
-    UsageAuditAggregationQuery, UsageAuditKeywordSearchQuery, UsageAuditListQuery,
-    UsageAuditSummaryQuery, UsageBodyCaptureResult, UsageBodyCaptureState, UsageBodyCaptureStorage,
-    UsageBodyField, UsageBreakdownGroupBy, UsageBreakdownSummaryQuery,
+    StoredUsageTimeSeriesBucket, StoredUsageUserTotals, UpsertUsageRecord,
+    UsageAuditAggregationGroupBy, UsageAuditAggregationQuery, UsageAuditKeywordSearchQuery,
+    UsageAuditListQuery, UsageAuditSummaryQuery, UsageBodyCaptureResult, UsageBodyCaptureState,
+    UsageBodyCaptureStorage, UsageBodyField, UsageBreakdownGroupBy, UsageBreakdownSummaryQuery,
     UsageCacheAffinityHitSummaryQuery, UsageCacheAffinityIntervalGroupBy,
     UsageCacheAffinityIntervalQuery, UsageCacheHitSummaryQuery, UsageCostSavingsSummaryQuery,
     UsageDailyHeatmapQuery, UsageDashboardDailyBreakdownQuery, UsageDashboardProviderCountsQuery,