tests: add first test for auth

CMakeLists.txt

@@ -10,10 +10,13 @@ find_package(Qt6 REQUIRED COMPONENTS
         Gui
         Widgets
         Network
+        Test
 )
 
 qt_standard_project_setup(REQUIRES 6.8)
 
+enable_testing()
+
 qt_add_executable(llink
         main.cpp
         src/MainWindow.cpp
@@ -56,6 +59,8 @@ target_link_libraries(llink
         Qt6::Network
 )
 
+add_subdirectory(tests)
+
 include(GNUInstallDirs)
 install(TARGETS llink
         BUNDLE DESTINATION .