Add Lua 5.4 scripting integration for dynamic game loading

- Integrated Lua 5.4 engine (32-bit mode for embedded ARM)
- Created LuaGame wrapper class implementing Game interface
- Added C++ bindings exposing renderer, game state, and input to Lua
- Implemented SD card loader for automatic .lua game discovery
- Updated GameLauncher to support std::function for lambda captures
- Made Game class members public for Lua bindings access
- Added example Lua games: counter, snake, bouncing ball
- Included comprehensive API documentation

Games can now be written as .lua text files on SD card and loaded
without recompilation. Build size: 747KB UF2, Lua VM uses ~50-80KB RAM.

games/lua_game_loader.h

@@ -0,0 +1,40 @@
+// ============================================================================
+// LUA GAME LOADER - HEADER
+// ============================================================================
+// Scans SD card for .lua game scripts and registers them with GameLauncher
+
+#ifndef LUA_GAME_LOADER_H
+#define LUA_GAME_LOADER_H
+
+#include "../lib/game_launcher.h"
+
+/**
+ * @brief Lua Game Loader - discovers and registers Lua games from SD card
+ */
+class LuaGameLoader {
+public:
+    /**
+     * @brief Scan SD card /games directory and register all .lua files
+     * @param launcher GameLauncher to register games with
+     * @return Number of Lua games found and registered
+     */
+    static int register_all_games(GameLauncher* launcher);
+
+private:
+    /**
+     * @brief Parse metadata from Lua script comments
+     * @param script_path Path to .lua file
+     * @param name Output: game name (default: filename)
+     * @param description Output: game description (default: empty)
+     * @return true if file could be read
+     */
+    static bool parse_metadata(const char* script_path, char* name, char* description);
+    
+    /**
+     * @brief Factory function for creating LuaGame instances
+     */
+    static Game* create_lua_game(const char* script_path, uint16_t width, uint16_t height,
+                                  LowLevelRenderer* renderer, LowLevelGUI* gui, InputManager* input_manager);
+};
+
+#endif // LUA_GAME_LOADER_H