feat(routing): 引入多执行池智能调度

将 Worker 发现、路由画像、容量与执行传输抽象为平台无关接口，新增 Kubernetes 和静态容量适配器，并以 shadow 模式接入生产配置。

实现网络与容量评分、路由防抖、池队列、同步 Worker 租约、一次性执行令牌，以及提交状态不明时禁止重复分配的安全语义。

新增 0105 兼容迁移、管理接口、指标、OpenAPI 和回归测试。已执行全量 Go 测试、go vet、OpenAPI、迁移安全、Compose 与 Kustomize 验证。

apps/api/internal/securityevents/metrics.go

@@ -96,6 +96,14 @@ type Metrics struct {
 	candidateDisabledSkipped    atomic.Uint64
 	candidateAllFullQueued      atomic.Uint64
 	candidateRoutingOther       atomic.Uint64
+	executionPoolSelected       atomic.Uint64
+	executionPoolShadow         atomic.Uint64
+	executionPoolUnavailable    atomic.Uint64
+	executionPoolCapacityReject atomic.Uint64
+	routeProbeHealthy           atomic.Uint64
+	routeProbeDegraded          atomic.Uint64
+	routeProbeUnreachable       atomic.Uint64
+	routeProbeUnknown           atomic.Uint64
 	storageAliyunWrites         atomic.Uint64
 	storageAliyunFailures       atomic.Uint64
 	storageAliyunWriteNanos     atomic.Uint64
@@ -324,6 +332,32 @@ func (m *Metrics) ObserveCandidateRouting(reason string) {
 	}
 }
 
+func (m *Metrics) ObserveExecutionPoolRouting(outcome string) {
+	switch outcome {
+	case "selected":
+		m.executionPoolSelected.Add(1)
+	case "shadow":
+		m.executionPoolShadow.Add(1)
+	case "capacity_rejected":
+		m.executionPoolCapacityReject.Add(1)
+	default:
+		m.executionPoolUnavailable.Add(1)
+	}
+}
+
+func (m *Metrics) ObserveRouteProbe(state string) {
+	switch state {
+	case "healthy":
+		m.routeProbeHealthy.Add(1)
+	case "degraded":
+		m.routeProbeDegraded.Add(1)
+	case "unreachable":
+		m.routeProbeUnreachable.Add(1)
+	default:
+		m.routeProbeUnknown.Add(1)
+	}
+}
+
 func (m *Metrics) ObserveObjectStorage(event string, provider string, bytes int64, duration time.Duration) {
 	provider = strings.ToLower(strings.TrimSpace(provider))
 	if duration < 0 {
@@ -612,6 +646,18 @@ func (m *Metrics) Handler(provider MetricsSnapshotProvider, issuer, audience str
 			{"all_full_queued", m.candidateAllFullQueued.Load()},
 			{"other", m.candidateRoutingOther.Load()},
 		})
+		outcomeCounters(w, "easyai_gateway_execution_pool_routing_total", "Execution-pool routing decisions by bounded outcome.", []outcomeValue{
+			{"selected", m.executionPoolSelected.Load()},
+			{"shadow", m.executionPoolShadow.Load()},
+			{"unavailable", m.executionPoolUnavailable.Load()},
+			{"capacity_rejected", m.executionPoolCapacityReject.Load()},
+		})
+		outcomeCounters(w, "easyai_gateway_route_probe_total", "Non-billable route probes by resulting state.", []outcomeValue{
+			{"healthy", m.routeProbeHealthy.Load()},
+			{"degraded", m.routeProbeDegraded.Load()},
+			{"unreachable", m.routeProbeUnreachable.Load()},
+			{"unknown", m.routeProbeUnknown.Load()},
+		})
 		storageProtocolCounters(w, "easyai_gateway_storage_write_attempts_total", "Object storage write attempts by bounded protocol.",
 			m.storageAliyunWrites.Load(), m.storageS3Writes.Load(), m.storageServerMainWrites.Load())
 		storageProtocolCounters(w, "easyai_gateway_storage_write_failures_total", "Object storage write failures by bounded protocol.",