fix(controller): enforce ownership on notification group, NAT server, and batch move

Co-authored-by: naiba/CloudCode <hi+cloudcode@nai.ba>

cmd/dashboard/controller/permissions.go

@@ -0,0 +1,51 @@
+package controller
+
+import (
+	"github.com/gin-gonic/gin"
+
+	"github.com/nezhahq/nezha/model"
+	"github.com/nezhahq/nezha/service/singleton"
+)
+
+func callerIsAdmin(c *gin.Context) bool {
+	auth, ok := c.Get(model.CtxKeyAuthorizedUser)
+	if !ok {
+		return false
+	}
+	user, ok := auth.(*model.User)
+	if !ok || user == nil {
+		return false
+	}
+	return user.Role.IsAdmin()
+}
+
+func userCanViewServer(c *gin.Context, server *model.Server) bool {
+	if server == nil {
+		return false
+	}
+	if callerIsAdmin(c) {
+		return true
+	}
+	if _, isMember := c.Get(model.CtxKeyAuthorizedUser); isMember {
+		if server.HasPermission(c) {
+			return true
+		}
+		return !server.HideForGuest
+	}
+	return !server.HideForGuest
+}
+
+func assertOwnsNotificationGroup(c *gin.Context, groupID uint64) error {
+	if groupID == 0 {
+		return nil
+	}
+
+	var ng model.NotificationGroup
+	if err := singleton.DB.First(&ng, groupID).Error; err != nil {
+		return singleton.Localizer.ErrorT("notification group id %d does not exist", groupID)
+	}
+	if !ng.HasPermission(c) {
+		return singleton.Localizer.ErrorT("permission denied")
+	}
+	return nil
+}