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/controllers/cluster.go

@@ -1,14 +1,58 @@
 package controllers
 
 import (
+	"context"
 	"opsxloki/dto"
 	"opsxloki/models"
 	"opsxloki/services"
 	"opsxloki/utils"
+	"time"
 
 	"github.com/gin-gonic/gin"
 )
 
+func (ctrl *ClusterController) Namespaces(c *gin.Context) {
+	id, err := utils.IntParam(c, "id")
+	if err != nil {
+		utils.BadRequest(c, "ID 无效")
+		return
+	}
+	cluster, err := ctrl.service.Get(uint(id))
+	if err != nil {
+		utils.NotFound(c, "集群不存在")
+		return
+	}
+	ctx, cancel := context.WithTimeout(c.Request.Context(), 12*time.Second)
+	defer cancel()
+	items, err := services.ListClusterNamespaces(ctx, cluster)
+	if err != nil {
+		utils.Error(c, 400, err.Error())
+		return
+	}
+	utils.Success(c, gin.H{"namespaces": items})
+}
+
+func (ctrl *ClusterController) Deployments(c *gin.Context) {
+	id, err := utils.IntParam(c, "id")
+	if err != nil {
+		utils.BadRequest(c, "ID 无效")
+		return
+	}
+	cluster, err := ctrl.service.Get(uint(id))
+	if err != nil {
+		utils.NotFound(c, "集群不存在")
+		return
+	}
+	ctx, cancel := context.WithTimeout(c.Request.Context(), 12*time.Second)
+	defer cancel()
+	items, err := services.ListClusterDeployments(ctx, cluster, c.Param("namespace"))
+	if err != nil {
+		utils.Error(c, 400, err.Error())
+		return
+	}
+	utils.Success(c, gin.H{"deployments": items})
+}
+
 type ClusterController struct {
 	service *services.ClusterService
 }