chore(lua): refactor addon Lua engine API + progress docs

- Refactor Lua addon integration:
  - Update CMakeLists.txt for addon build paths
  - Enhance addons API headers and Lua engine interface
  - Add new Lua API addon modules (`lua_api_helpers`, `lua_api_registrations`, `lua_services`, `lua_action_api`, `lua_inventory_api`, `lua_quest_api`, `lua_social_api`, `lua_spell_api`, `lua_system_api`, `lua_unit_api`)
  - Update implementation in addon_manager.cpp, lua_engine.cpp, application.cpp, game_handler.cpp

include/addons/lua_services.hpp

@@ -0,0 +1,17 @@
+// lua_services.hpp — Dependency-injected services for Lua bindings.
+// Replaces Application::getInstance() calls in domain API files (§5.2).
+#pragma once
+
+namespace wowee::core  { class Window; }
+namespace wowee::audio { class AudioCoordinator; }
+namespace wowee::game  { class ExpansionRegistry; }
+
+namespace wowee::addons {
+
+struct LuaServices {
+    core::Window*            window            = nullptr;
+    audio::AudioCoordinator* audioCoordinator  = nullptr;
+    game::ExpansionRegistry* expansionRegistry = nullptr;
+};
+
+} // namespace wowee::addons