chore(application): extract appearance controller and unify UI flow

- Refactor UI application architecture: extracted appearance controller into ui_services.hpp + implementation updates
- Update UI components and managers to use new service layer:
  - `action_bar_panel`, `auth_screen`, `character_screen`, `chat_panel`, `combat_ui`, `dialog_manager`, `game_screen`, `settings_panel`, `social_panel`, `toast_manager`, `ui_manager`, `window_manager`
- Adjust core application entrypoints:
  - application.cpp
- Update component implementations for new controller flow:
  - action_bar_panel.cpp, `chat_panel.cpp`, `combat_ui.cpp`, `dialog_manager.cpp`, `game_screen.cpp`, `settings_panel.cpp`, `social_panel.cpp`, `toast_manager.cpp`, `window_manager.cpp`

These staged changes implement a major architectural refactor for UI/appearance controller separation

include/ui/auth_screen.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "ui/ui_services.hpp"
 #include "auth/auth_handler.hpp"
 #include <vulkan/vulkan.h>
 #include <string>
@@ -30,6 +31,9 @@ public:
      */
     void setOnSuccess(std::function<void()> callback) { onSuccess = callback; }
 
+    /// Set services (dependency injection)
+    void setServices(const UIServices& services) { services_ = services; }
+
 
     /**
      * Check if authentication is in progress
@@ -44,6 +48,8 @@ public:
     const std::string& getStatusMessage() const { return statusMessage; }
 
 private:
+    UIServices services_;  // Injected service references
+
     struct ServerProfile {
         std::string hostname;
         int port = 3724;