feat(data): 废弃 usage 表 HTTP/结算列，迁移至 settlement_snapshots 与 http_audits

- 新增迁移 20260413030000：标记 billing_status、finalized_at、request_headers 等列为 DEPRECATED
- 更新 baseline_v2.sql 同步废弃注释，BASELINE_V2_CUTOFF_VERSION 升至 20260413030000
- usage/sql.rs：inline body 阈值归零，强制所有 body 走 blob 存储；upsert 时清空 legacy header/output_price 列
- 查询层优先读 usage_settlement_snapshots 的 billing_status、finalized_at、output_price_per_1m
- runtime.rs：stale usage 处理同步写入 usage_settlement_snapshots；SELECT FOR UPDATE 改为 FOR UPDATE OF usage
- 前端：PerformanceAnalysis 页面重构为实时面板，新增 prometheus 工具函数与 monitoring API

apps/aether-gateway/src/maintenance/runtime/tests.rs

@@ -29,7 +29,8 @@ use super::{
     usage_cleanup_window, wallet_daily_usage_aggregation_target, AppState, DbMaintenanceRunSummary,
     FailedPendingUsageRow, GatewayDataState, ProxyUpgradeRolloutProbeConfig, StalePendingUsageRow,
     UsageCleanupSettings, DELETE_STALE_WALLET_DAILY_USAGE_LEDGERS_SQL,
-    SELECT_WALLET_DAILY_USAGE_AGGREGATION_ROWS_SQL, USAGE_CLEANUP_HOUR, USAGE_CLEANUP_MINUTE,
+    SELECT_STALE_PENDING_USAGE_BATCH_SQL, SELECT_WALLET_DAILY_USAGE_AGGREGATION_ROWS_SQL,
+    UPDATE_FAILED_VOID_STALE_USAGE_SQL, USAGE_CLEANUP_HOUR, USAGE_CLEANUP_MINUTE,
     WALLET_DAILY_USAGE_AGGREGATION_HOUR, WALLET_DAILY_USAGE_AGGREGATION_MINUTE,
 };
 
@@ -90,6 +91,15 @@ fn wallet_daily_usage_queries_use_settlement_snapshots_for_wallet_identity() {
         .contains("usage_settlement_snapshots.wallet_id = ledgers.wallet_id"));
 }
 
+#[test]
+fn pending_cleanup_queries_use_settlement_snapshots_for_billing_authority() {
+    assert!(SELECT_STALE_PENDING_USAGE_BATCH_SQL.contains("LEFT JOIN usage_settlement_snapshots"));
+    assert!(SELECT_STALE_PENDING_USAGE_BATCH_SQL
+        .contains("COALESCE(usage_settlement_snapshots.billing_status, usage.billing_status)"));
+    assert!(UPDATE_FAILED_VOID_STALE_USAGE_SQL.contains("INSERT INTO usage_settlement_snapshots"));
+    assert!(UPDATE_FAILED_VOID_STALE_USAGE_SQL.contains("billing_status = EXCLUDED.billing_status"));
+}
+
 fn sample_connected_proxy_node(
     node_id: &str,
     heartbeat_interval: i32,