Add rom.data.add_granny_file and add_package_file Lua APIs (#27)

Allows mods to register custom GPK/PKG files for file-redirection
at runtime, after the initial plugins_data scan has completed.

This enables mods that generate assets during Lua plugin init
(before LoadAllModelAndAnimationData runs) to have those assets
picked up by the game's normal loading path without requiring
a restart.

Co-authored-by: enderclem <enderclem@gmail.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 3 people

src/lua_extensions/bindings/hades/data.cpp

@@ -20,6 +20,10 @@ namespace sgg
 	};
 } // namespace sgg
 
+// Defined in main.cpp — file redirect maps for custom GPK/PKG assets
+extern std::unordered_map<std::string, std::string> additional_granny_files;
+extern std::unordered_map<std::string, std::string> additional_package_files;
+
 namespace lua::hades::data
 {
 	static std::recursive_mutex g_load_packages_overrides_mutex;
@@ -145,6 +149,41 @@ namespace lua::hades::data
 		LOG(INFO) << ss.str();
 	}
 
+	// Lua API: Function
+	// Table: data
+	// Name: add_granny_file
+	// Param: filename: string: The GPK filename (e.g. "Melinoe.gpk").
+	// Param: full_path: string: The full filesystem path to the GPK file.
+	// Registers a custom GPK file for file-redirection at runtime, allowing
+	// hot-loading of GPK assets that were not present during initial scan.
+	//
+	// **Example Usage:**
+	// ```lua
+	// rom.data.add_granny_file("Melinoe.gpk", "C:/path/to/plugins_data/CG3HBuilder/Melinoe.gpk")
+	// ```
+	static void add_granny_file(const std::string& filename, const std::string& full_path)
+	{
+		additional_granny_files[filename] = full_path;
+		LOG(INFO) << "Adding to granny files (runtime): " << full_path;
+	}
+
+	// Lua API: Function
+	// Table: data
+	// Name: add_package_file
+	// Param: filename: string: The PKG or PKG_MANIFEST filename.
+	// Param: full_path: string: The full filesystem path to the file.
+	// Registers a custom PKG/PKG_MANIFEST file for file-redirection at runtime.
+	//
+	// **Example Usage:**
+	// ```lua
+	// rom.data.add_package_file("MyMod.pkg", "C:/path/to/plugins_data/MyMod/MyMod.pkg")
+	// ```
+	static void add_package_file(const std::string& filename, const std::string& full_path)
+	{
+		additional_package_files[filename] = full_path;
+		LOG(INFO) << "Adding to package files (runtime): " << full_path;
+	}
+
 	static std::unordered_map<void*, std::filesystem::path> g_sjson_FileStream_to_filepath;
 	static constexpr size_t g_sjson_size_multiplier_for_patches = 8;
 
@@ -444,6 +483,8 @@ namespace lua::hades::data
 
 		ns.set_function("load_package_overrides_get", load_package_overrides_get);
 		ns.set_function("load_package_overrides_set", load_package_overrides_set);
+		ns.set_function("add_granny_file", add_granny_file);
+		ns.set_function("add_package_file", add_package_file);
 
 		state["sol.__h2m_LoadPackages__"] = state["LoadPackages"];
 		// Lua API: Function