feat: 新增「部署客户端」日志采集器模块

三种采集器（host-promtail / k8s-daemonset / k8s-fluentbit-sidecar），每种关联已部署 Loki：
- host-promtail：SSH 安装 Promtail（复用 deployBinary）
- k8s-daemonset：helm 安装 Promtail DaemonSet（复用 deployHelm）
- k8s-fluentbit-sidecar：kubectl patch 注入 Fluent Bit sidecar

含 Collector 数据模型、三个部署器、配置模板、CRUD API、前端页面。
附带 UI 优化：ErrorBoundary、部署卡片浏览器访问按钮、菜单名称调整。

Co-Authored-By: Claude <noreply@anthropic.com>

backend/controllers/collector.go

@@ -0,0 +1,122 @@
+package controllers
+
+import (
+	"lokideploy/models"
+	"lokideploy/services"
+	"lokideploy/utils"
+
+	"github.com/gin-gonic/gin"
+)
+
+type CollectorController struct {
+	service *services.CollectorService
+}
+
+func NewCollectorController() *CollectorController {
+	return &CollectorController{service: services.NewCollectorService()}
+}
+
+type CreateCollectorRequest struct {
+	Name             string `json:"name" binding:"required"`
+	Type             string `json:"type" binding:"required"`
+	LokiDeploymentID uint   `json:"lokiDeploymentID" binding:"required"`
+	HostID           *uint  `json:"hostID"`
+	ClusterID        *uint  `json:"clusterID"`
+	TargetDeployment string `json:"targetDeployment"`
+	Namespace        string `json:"namespace"`
+	LogPath          string `json:"logPath"`
+	Labels           string `json:"labels"`
+}
+
+func (ctrl *CollectorController) Create(c *gin.Context) {
+	var req CreateCollectorRequest
+	if !utils.BindAndValidate(c, &req) {
+		return
+	}
+	collector, err := ctrl.service.Create(&services.CreateCollectorRequest{
+		Name: req.Name, Type: req.Type, LokiDeploymentID: req.LokiDeploymentID,
+		HostID: req.HostID, ClusterID: req.ClusterID, TargetDeployment: req.TargetDeployment,
+		Namespace: req.Namespace, LogPath: req.LogPath, Labels: req.Labels,
+	})
+	if err != nil {
+		utils.Error(c, 400, err.Error())
+		return
+	}
+	utils.Success(c, models.SanitizedJSON(collector))
+}
+
+func (ctrl *CollectorController) Get(c *gin.Context) {
+	id, err := utils.IntParam(c, "id")
+	if err != nil {
+		utils.BadRequest(c, "ID 无效")
+		return
+	}
+	collector, err := ctrl.service.Get(uint(id))
+	if err != nil {
+		utils.NotFound(c, "采集器不存在")
+		return
+	}
+	utils.Success(c, models.SanitizedJSON(collector))
+}
+
+func (ctrl *CollectorController) List(c *gin.Context) {
+	page, pageSize := utils.Pagination(c)
+	collectors, total, err := ctrl.service.List(page, pageSize)
+	if err != nil {
+		utils.Error(c, 500, err.Error())
+		return
+	}
+	utils.Success(c, utils.PageData{
+		List: models.SanitizedJSON(collectors), Total: total, Page: page, PageSize: pageSize,
+	})
+}
+
+func (ctrl *CollectorController) Update(c *gin.Context) {
+	id, err := utils.IntParam(c, "id")
+	if err != nil {
+		utils.BadRequest(c, "ID 无效")
+		return
+	}
+	var updates map[string]interface{}
+	if !utils.BindAndValidate(c, &updates) {
+		return
+	}
+	if err := ctrl.service.Update(uint(id), updates); err != nil {
+		utils.Error(c, 400, err.Error())
+		return
+	}
+	utils.Success(c, gin.H{"message": "更新成功"})
+}
+
+func (ctrl *CollectorController) Delete(c *gin.Context) {
+	id, err := utils.IntParam(c, "id")
+	if err != nil {
+		utils.BadRequest(c, "ID 无效")
+		return
+	}
+	if err := ctrl.service.Delete(uint(id)); err != nil {
+		utils.Error(c, 400, err.Error())
+		return
+	}
+	utils.Success(c, gin.H{"message": "删除成功"})
+}
+
+func (ctrl *CollectorController) Install(c *gin.Context) {
+	id, err := utils.IntParam(c, "id")
+	if err != nil {
+		utils.BadRequest(c, "ID 无效")
+		return
+	}
+	go ctrl.service.Install(uint(id))
+	utils.Success(c, gin.H{"message": "已开始部署采集器"})
+}
+
+func (ctrl *CollectorController) Uninstall(c *gin.Context) {
+	id, err := utils.IntParam(c, "id")
+	if err != nil {
+		utils.BadRequest(c, "ID 无效")
+		return
+	}
+	go ctrl.service.Uninstall(uint(id))
+	utils.Success(c, gin.H{"message": "已开始卸载采集器"})
+}