add basic types and fix cmake

src/lib/config/ConfigLoader.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <string>
+
+#include "GameConfig.h"
+
+// Parses the five simulation TOML files from a directory and returns a fully
+// populated, immutable GameConfig. Throws std::runtime_error on any parse or
+// validation failure; the exception message identifies the offending file,
+// field, or formula (see architecture.md "Config Loading").
+//
+// Per-file helpers are exposed so tests can exercise individual loaders in
+// isolation.
+class ConfigLoader
+{
+public:
+    static GameConfig loadFromDirectory(const std::string& configDir);
+
+    static WorldConfig loadWorld(const std::string& path);
+    static BuildingsConfig loadBuildings(const std::string& path);
+    static RecipesConfig loadRecipes(const std::string& path);
+    static ShipsConfig loadShips(const std::string& path);
+    static StationsConfig loadStations(const std::string& path);
+};