🐛 fix(core): enforce strict LSP lifecycle

lsp-server/test/test_provider/test_main.cppm

@@ -6,6 +6,7 @@ import std;
 
 import lsp.test.framework;
 import lsp.test.provider.completion;
+import lsp.test.provider.core_server_fixture;
 import lsp.test.provider.definitions;
 import lsp.test.provider.interpreter;
 import lsp.test.provider.json_flow;
@@ -26,9 +27,9 @@ export int Run(int argc, char** argv)
     {
         std::string_view arg(argv[i]);
 
-        if (arg == "--exit-provider")
+        if (arg == "--core-server-fixture")
         {
-            return lsp::test::provider::RunExitProviderChild();
+            return lsp::test::provider::RunCoreServerFixture();
         }
 
         constexpr std::string_view kInterpreterPrefix = "--interpreter=";