feat: overhaul groups management, remove global team_admin and isolate group administration

internal/domain/models.go

@@ -98,7 +98,7 @@ type User struct {
 	Username            string   `json:"username,omitempty"`
 	PasswordHash        string   `json:"-"`
 	DisplayName         string   `json:"displayName"`
-	Role                string   `json:"role"` // admin | team_admin | member
+	Role                string   `json:"role"` // admin | member
 	IsActive            bool     `json:"isActive"`
 	AlarmChannels       []string `json:"alarmChannels"` // email | discord | webhook
 	AlarmEmail          string   `json:"alarmEmail"`
@@ -112,7 +112,7 @@ type UserInvite struct {
 	ID        string `json:"id"`
 	Code      string `json:"code"`
 	Email     string `json:"email,omitempty"`
-	Role      string `json:"role"` // member | team_admin | admin
+	Role      string `json:"role"` // member | admin
 	TeamID    string `json:"teamId,omitempty"`
 	TeamName  string `json:"teamName,omitempty"`
 	CreatedBy string `json:"createdBy"`
@@ -212,7 +212,7 @@ type Organization struct {
 
 type Team struct {
 	ID          string       `json:"id"`
-	OrgID       string       `json:"orgId"`
+	OrgID       string       `json:"orgId,omitempty"`
 	Name        string       `json:"name"`
 	Description string       `json:"description"`
 	Members     []TeamMember `json:"members"`
@@ -224,7 +224,7 @@ type TeamMember struct {
 	UserID      string `json:"userId"`
 	DisplayName string `json:"displayName"`
 	Email       string `json:"email"`
-	Role        string `json:"role"` // team_admin | member | owner
+	Role        string `json:"role"` // admin | member
 	JoinedAt    string `json:"joinedAt"`
 }