♻️ refactor(lsp_server): move entrypoints out of named modules

- export Run() from launcher module and add non-module main TU
- apply same pattern to module-based test executables
- migrate utils/string implementation fully into string.cppm and drop string.cpp
- point clangd to linux build compilation database

lsp-server/src/cli/launcher.cppm

@@ -0,0 +1,46 @@
+module;
+
+export module lsp.cli.launcher;
+
+import spdlog;
+import std;
+
+import lsp.core.server;
+import lsp.utils.args_parser;
+
+export int Run(int argc, char* argv[])
+{
+    lsp::utils::ArgsParser& args_parser = lsp::utils::ArgsParser::Instance();
+    auto& config = args_parser.Parse(argc, argv);
+
+    if (config.show_help)
+    {
+        lsp::utils::ArgsParser::PrintHelp(argv[0]);
+        return 0;
+    }
+
+    lsp::utils::ArgsParser::SetupLogger(config);
+
+    try
+    {
+        spdlog::info("TSL-LSP server starting...");
+        lsp::core::LspServer server(config.thread_count);
+        server.Run();
+    }
+    catch (const std::exception& e)
+    {
+        std::cerr << "[TSL-LSP] Server fatal error: " << e.what() << std::endl;
+        spdlog::error("Server fatal error: {}", e.what());
+        return 1;
+    }
+    catch (...)
+    {
+        std::cerr << "[TSL-LSP] Server unknown fatal error" << std::endl;
+        spdlog::error("Server unknown fatal error");
+        return 1;
+    }
+
+    spdlog::info("TSL-LSP server stopped normally");
+    spdlog::shutdown();
+    return 0;
+}