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

frontend/src/api/dashboard.ts

@@ -183,6 +183,18 @@ export interface RequestDetail {
   has_response_body?: boolean
   has_client_response_body?: boolean
   metadata?: Record<string, unknown>
+  settlement?: {
+    billing_snapshot?: Record<string, unknown>
+    billing_snapshot_schema_version?: string
+    billing_snapshot_status?: string
+    rate_multiplier?: number
+    is_free_tier?: boolean
+    input_price_per_1m?: number
+    output_price_per_1m?: number
+    cache_creation_price_per_1m?: number
+    cache_read_price_per_1m?: number
+    price_per_request?: number
+  } | null
   // 阶梯计费信息
   tiered_pricing?: {
     total_input_context: number  // 总输入上下文 (input + cache_read)

frontend/src/api/monitoring.ts

@@ -0,0 +1,208 @@
+import apiClient from './client'
+import {
+  findMetricValueNumber,
+  parsePrometheusSamples,
+  sumMetricValues,
+} from '@/utils/prometheus'
+
+export interface AdminMonitoringSystemStatus {
+  timestamp: string
+  users: {
+    total: number
+    active: number
+  }
+  providers: {
+    total: number
+    active: number
+  }
+  api_keys: {
+    total: number
+    active: number
+  }
+  today_stats: {
+    requests: number
+    tokens: number
+    cost_usd: string
+  }
+  tunnel: {
+    proxy_connections: number
+    nodes: number
+    active_streams: number
+  }
+  internal_gateway: {
+    status: string
+    path_prefixes: string[]
+  }
+  recent_errors: number
+}
+
+export interface AdminMonitoringCircuitBreakerSummary {
+  state: string
+  provider_id?: string
+  provider_name?: string | null
+  key_name?: string | null
+  health_score?: number
+  consecutive_failures?: number
+  last_failure_at?: string | null
+  open_formats?: string[]
+}
+
+export interface AdminMonitoringErrorStatistics {
+  total_errors: number
+  active_keys: number
+  degraded_keys: number
+  unhealthy_keys: number
+  open_circuit_breakers: number
+  circuit_breakers: Record<string, AdminMonitoringCircuitBreakerSummary>
+}
+
+export interface AdminMonitoringRecentError {
+  error_id: string
+  error_type: string
+  operation: string
+  timestamp: string | null
+  context: {
+    request_id?: string | null
+    provider_id?: string | null
+    provider_name?: string | null
+    model?: string | null
+    api_format?: string | null
+    status_code?: number | null
+    error_message?: string | null
+  }
+}
+
+export interface AdminMonitoringResilienceStatus {
+  timestamp: string
+  health_score: number
+  status: 'healthy' | 'degraded' | 'critical' | string
+  error_statistics: AdminMonitoringErrorStatistics
+  recent_errors: AdminMonitoringRecentError[]
+  recommendations: string[]
+}
+
+export interface AdminMonitoringCircuitHistoryItem {
+  event: string
+  key_id: string
+  provider_id: string
+  provider_name?: string | null
+  key_name?: string | null
+  api_format?: string | null
+  reason?: string | null
+  recovery_seconds?: number | null
+  timestamp?: string | null
+}
+
+export interface AdminMonitoringCircuitHistoryResponse {
+  items: AdminMonitoringCircuitHistoryItem[]
+  count: number
+}
+
+export interface GatewayGateMetrics {
+  inFlight: number | null
+  availablePermits: number | null
+  highWatermark: number | null
+  rejectedTotal: number | null
+  unavailable: boolean
+}
+
+export interface GatewayFallbackMetricSummary {
+  name: string
+  label: string
+  total: number
+}
+
+export interface GatewayMetricsSummary {
+  serviceUp: number | null
+  local: GatewayGateMetrics
+  distributed: GatewayGateMetrics
+  tunnel: {
+    proxyConnections: number | null
+    nodes: number | null
+    activeStreams: number | null
+  }
+  fallbackTotal: number
+  fallbacks: GatewayFallbackMetricSummary[]
+}
+
+const FALLBACK_METRICS: Array<{ name: string; label: string }> = [
+  { name: 'decision_remote_total', label: '远端决策回退' },
+  { name: 'plan_fallback_total', label: 'Plan 回退' },
+  { name: 'control_execute_fallback_total', label: '控制执行回退' },
+  { name: 'remote_execute_emergency_total', label: '紧急远端执行' },
+  { name: 'local_execution_runtime_miss_total', label: '本地运行时缺失' },
+]
+
+function buildGateMetrics(
+  samples: ReturnType<typeof parsePrometheusSamples>,
+  gate: string
+): GatewayGateMetrics {
+  return {
+    inFlight: findMetricValueNumber(samples, 'concurrency_in_flight', { gate }),
+    availablePermits: findMetricValueNumber(samples, 'concurrency_available_permits', { gate }),
+    highWatermark: findMetricValueNumber(samples, 'concurrency_high_watermark', { gate }),
+    rejectedTotal: findMetricValueNumber(samples, 'concurrency_rejected_total', { gate }),
+    unavailable: findMetricValueNumber(samples, 'concurrency_unavailable', { gate }) === 1,
+  }
+}
+
+export function buildGatewayMetricsSummary(text: string): GatewayMetricsSummary {
+  const samples = parsePrometheusSamples(text)
+  const fallbacks = FALLBACK_METRICS.map(item => ({
+    ...item,
+    total: sumMetricValues(samples, item.name),
+  }))
+
+  return {
+    serviceUp: findMetricValueNumber(samples, 'service_up', { service: 'aether-gateway' }),
+    local: buildGateMetrics(samples, 'gateway_requests'),
+    distributed: buildGateMetrics(samples, 'gateway_requests_distributed'),
+    tunnel: {
+      proxyConnections: findMetricValueNumber(samples, 'tunnel_proxy_connections'),
+      nodes: findMetricValueNumber(samples, 'tunnel_nodes'),
+      activeStreams: findMetricValueNumber(samples, 'tunnel_active_streams'),
+    },
+    fallbackTotal: fallbacks.reduce((total, item) => total + item.total, 0),
+    fallbacks,
+  }
+}
+
+async function fetchGatewayMetricsText(): Promise<string> {
+  const response = await apiClient.get<string>('/_gateway/metrics', {
+    responseType: 'text',
+    transformResponse: [(data: string) => data],
+  })
+  return typeof response.data === 'string' ? response.data : String(response.data ?? '')
+}
+
+export const monitoringApi = {
+  async getSystemStatus(): Promise<AdminMonitoringSystemStatus> {
+    const response = await apiClient.get<AdminMonitoringSystemStatus>(
+      '/api/admin/monitoring/system-status'
+    )
+    return response.data
+  },
+
+  async getResilienceStatus(): Promise<AdminMonitoringResilienceStatus> {
+    const response = await apiClient.get<AdminMonitoringResilienceStatus>(
+      '/api/admin/monitoring/resilience-status'
+    )
+    return response.data
+  },
+
+  async getCircuitHistory(limit = 10): Promise<AdminMonitoringCircuitHistoryResponse> {
+    const response = await apiClient.get<AdminMonitoringCircuitHistoryResponse>(
+      '/api/admin/monitoring/resilience/circuit-history',
+      { params: { limit } }
+    )
+    return response.data
+  },
+
+  async getGatewayMetricsText(): Promise<string> {
+    return fetchGatewayMetricsText()
+  },
+
+  async getGatewayMetricsSummary(): Promise<GatewayMetricsSummary> {
+    return buildGatewayMetricsSummary(await fetchGatewayMetricsText())
+  },
+}