feat: complete kiro platform support

backend/internal/handler/admin/group_handler_kiro_validation_test.go

@@ -0,0 +1,16 @@
+package admin
+
+import (
+	"testing"
+
+	"github.com/gin-gonic/gin/binding"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGroupRequestValidationAcceptsKiroPlatform(t *testing.T) {
+	createReq := CreateGroupRequest{Name: "kiro-default", Platform: "kiro"}
+	require.NoError(t, binding.Validator.ValidateStruct(createReq))
+
+	updateReq := UpdateGroupRequest{Platform: "kiro"}
+	require.NoError(t, binding.Validator.ValidateStruct(updateReq))
+}