테넌트 관리자(Tenant Admin)의 본인 소유 테넌트 목록 조회 및 관리 기능 개선

backend/internal/handler/tenant_handler.go

@@ -109,9 +109,36 @@ func (h *TenantHandler) ListTenants(c *fiber.Ctx) error {
 		offset = 0
 	}
 
-	tenants, total, err := h.Service.ListTenants(c.Context(), limit, offset, parentId)
-	if err != nil {
-		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": err.Error()})
+	var tenants []domain.Tenant
+	var total int64
+	var err error
+
+	profile, _ := c.Locals("user_profile").(*domain.UserProfileResponse)
+
+	// If Tenant Admin, only list manageable tenants
+	if profile != nil && profile.Role == domain.RoleTenantAdmin {
+		slog.Info("Listing manageable tenants for tenant admin", "userID", profile.ID)
+		tenants, err = h.Service.ListManageableTenants(c.Context(), profile.ID)
+		if err != nil {
+			return errorJSON(c, fiber.StatusInternalServerError, "failed to list manageable tenants: "+err.Error())
+		}
+		total = int64(len(tenants))
+		// Apply basic pagination if needed (optional for usually small number of manageable tenants)
+		if offset < len(tenants) {
+			end := offset + limit
+			if end > len(tenants) {
+				end = len(tenants)
+			}
+			tenants = tenants[offset:end]
+		} else {
+			tenants = []domain.Tenant{}
+		}
+	} else {
+		// Super Admin case
+		tenants, total, err = h.Service.ListTenants(c.Context(), limit, offset, parentId)
+		if err != nil {
+			return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": err.Error()})
+		}
 	}
 
 	// Fetch member counts for all tenants in one query using slugs (company codes)