refactor: 统一 PKCE 挑战值生成逻辑

apps/api/internal/httpapi/oidc_session.go

@@ -48,7 +48,7 @@ func (s *Server) startOIDCLogin(w http.ResponseWriter, r *http.Request) {
 	if returnTo == "" {
 		returnTo = "/"
 	}
-	transaction, _, err := oidcsession.NewLoginTransaction(returnTo, time.Now())
+	transaction, err := oidcsession.NewLoginTransaction(returnTo, time.Now())
 	if err != nil {
 		writeError(w, http.StatusBadRequest, "登录后返回地址无效", errorCodeOIDCLoginInvalid)
 		return

apps/api/internal/httpapi/oidc_session_test.go

@@ -66,7 +66,7 @@ func TestCompleteOIDCLoginReportsSafeTransactionFailureReason(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	transaction, _, err := oidcsession.NewLoginTransaction("/", time.Now())
+	transaction, err := oidcsession.NewLoginTransaction("/", time.Now())
 	if err != nil {
 		t.Fatal(err)
 	}