feat: complete Loki query, insights, settings and deployment workflows

Add the Loki query UI, access policies, ingress insights, alert and registry settings, and their backend APIs. Include the related Kubernetes deployment and collector updates required by the integrated application.

Validated with go test ./..., npm run build, and npm run lint.

backend/services/cluster_workloads.go

@@ -0,0 +1,63 @@
+package services
+
+import (
+	"context"
+	"fmt"
+	"regexp"
+	"sort"
+	"time"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"opsxloki/models"
+)
+
+type ClusterDeploymentOption struct {
+	Name          string `json:"name"`
+	Replicas      int    `json:"replicas"`
+	ReadyReplicas int    `json:"readyReplicas"`
+}
+
+var kubernetesNamespacePattern = regexp.MustCompile(`^[a-z0-9]([-a-z0-9]*[a-z0-9])?$`)
+
+func ListClusterNamespaces(ctx context.Context, cluster *models.Cluster) ([]string, error) {
+	client, err := clusterClient(cluster, 10*time.Second)
+	if err != nil {
+		return nil, err
+	}
+	items, err := client.CoreV1().Namespaces().List(ctx, metav1.ListOptions{})
+	if err != nil {
+		return nil, fmt.Errorf("读取集群命名空间失败: %w", err)
+	}
+	result := make([]string, 0, len(items.Items))
+	for _, item := range items.Items {
+		result = append(result, item.Name)
+	}
+	sort.Strings(result)
+	return result, nil
+}
+
+func ListClusterDeployments(ctx context.Context, cluster *models.Cluster, namespace string) ([]ClusterDeploymentOption, error) {
+	if len(namespace) > 63 || !kubernetesNamespacePattern.MatchString(namespace) {
+		return nil, fmt.Errorf("命名空间名称无效")
+	}
+	client, err := clusterClient(cluster, 10*time.Second)
+	if err != nil {
+		return nil, err
+	}
+	items, err := client.AppsV1().Deployments(namespace).List(ctx, metav1.ListOptions{})
+	if err != nil {
+		return nil, fmt.Errorf("读取集群 Deployment 失败: %w", err)
+	}
+	result := make([]ClusterDeploymentOption, 0, len(items.Items))
+	for _, item := range items.Items {
+		replicas := int32(1)
+		if item.Spec.Replicas != nil {
+			replicas = *item.Spec.Replicas
+		}
+		result = append(result, ClusterDeploymentOption{
+			Name: item.Name, Replicas: int(replicas), ReadyReplicas: int(item.Status.ReadyReplicas),
+		})
+	}
+	sort.Slice(result, func(i, j int) bool { return result[i].Name < result[j].Name })
+	return result, nil
+}