feat(backend): add kiro account support

backend/internal/service/kiro_oauth_service_test.go

@@ -0,0 +1,51 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	kiropkg "github.com/Wei-Shaw/sub2api/internal/pkg/kiro"
+	"github.com/stretchr/testify/require"
+)
+
+func TestKiroIDCAuthRedirectURIUsesLoopbackIP(t *testing.T) {
+	require.Equal(t, "http://127.0.0.1:9876/oauth/callback", kiroIDCRedirectURI)
+}
+
+func TestKiroSocialAuthRedirectURIUsesLoopbackIP(t *testing.T) {
+	require.Equal(t, "http://localhost:49153", kiroSocialRedirectURI)
+}
+
+func TestBuildKiroSocialExchangeRedirectURIUsesProviderDefault(t *testing.T) {
+	require.Equal(
+		t,
+		"http://localhost:49153/oauth/callback?login_option=github",
+		buildKiroSocialExchangeRedirectURI("http://localhost:49153", "Github", "", ""),
+	)
+}
+
+func TestBuildKiroSocialExchangeRedirectURIPreservesParsedCallbackData(t *testing.T) {
+	require.Equal(
+		t,
+		"http://localhost:49153/signin/callback?login_option=google",
+		buildKiroSocialExchangeRedirectURI("http://localhost:49153", "Github", "/signin/callback", "google"),
+	)
+}
+
+func TestKiroOAuthService_ExchangeCodeRejectsExpiredSession(t *testing.T) {
+	svc := NewKiroOAuthService(nil)
+	svc.sessionStore.Set("expired-session", &kiropkg.AuthSession{
+		State:     "expected-state",
+		CreatedAt: time.Now().Add(-11 * time.Minute),
+	})
+
+	_, err := svc.ExchangeCode(context.Background(), &KiroExchangeCodeInput{
+		SessionID: "expired-session",
+		State:     "expected-state",
+		Code:      "auth-code",
+	})
+	require.EqualError(t, err, "session not found or expired")
+}