Add pagination to game launcher - 4 games per page

- GameLauncher now displays only 4 games per page to keep menu in bounds
- Added page navigation with page indicator (Page X/Y)
- KEY0 navigates between pages and within page
- KEY1 selects the highlighted game
- Touch selection works on current page only
- Helper methods: get_total_pages(), get_page_start_index(), get_page_end_index()
- Updated both lib/ and emulator/ versions for consistency

lib/game_launcher.h

@@ -95,11 +95,18 @@ private:
     std::vector<GameEntry> games;
     int selected_index;      // Currently highlighted game
     Game* selected_game;     // Currently running game (nullptr = in menu)
+    int current_page;        // Current page in pagination
     
     // Menu layout constants
     static const int MENU_Y_START = 60;
     static const int MENU_ITEM_HEIGHT = 40;
     static const int MENU_PADDING = 10;
+    static const int GAMES_PER_PAGE = 4;
+    
+    // Helper functions for pagination
+    int get_total_pages() const;
+    int get_page_start_index() const;
+    int get_page_end_index() const;
 };
 
 #endif // GAME_LAUNCHER_H