Add renderer.text_scaled() Lua binding

lua_bindings.cpp:
- Added new lua_renderer_text_scaled() function
- Wraps renderer->draw_string_scaled() with proper scale support
- Registered as renderer.text_scaled(x, y, text, on, scale)
- Scale parameter defaults to 1 if omitted

Updated all 4 games to use text_scaled():
- simon_says.lua: All text now uses text_scaled with scale=2
- tic_tac_toe.lua: All text now uses text_scaled with scale=2
- memory_match.lua: All text now uses text_scaled with scale=2
- 2048.lua: All text now uses text_scaled with scale=2

This properly uses the C++ renderer's scaled text rendering instead of
workarounds in Lua, providing better performance and consistency.

games/lua_bindings.cpp

@@ -125,6 +125,23 @@ static int lua_renderer_text(lua_State* L) {
     return 0;
 }
 
+// renderer.text_scaled(x, y, text, on, scale)
+static int lua_renderer_text_scaled(lua_State* L) {
+    LuaGame* game = get_game(L);
+    if (!game) return 0;
+    
+    int x = luaL_checkinteger(L, 1);
+    int y = luaL_checkinteger(L, 2);
+    const char* text = luaL_checkstring(L, 3);
+    bool on = lua_toboolean(L, 4);
+    int scale = lua_isnone(L, 5) ? 1 : luaL_checkinteger(L, 5);
+    
+    game->renderer->set_text_color(on);
+    game->renderer->draw_string_scaled(x, y, text, scale, 1);
+    
+    return 0;
+}
+
 // renderer.triangle(x0, y0, x1, y1, x2, y2, on, filled)
 static int lua_renderer_triangle(lua_State* L) {
     LuaGame* game = get_game(L);
@@ -281,6 +298,10 @@ void lua_bindings_register(lua_State* L, LuaGame* game) {
     lua_pushcfunction(L, lua_renderer_text);
     lua_settable(L, -3);
     
+    lua_pushstring(L, "text_scaled");
+    lua_pushcfunction(L, lua_renderer_text_scaled);
+    lua_settable(L, -3);
+    
     lua_pushstring(L, "triangle");
     lua_pushcfunction(L, lua_renderer_triangle);
     lua_settable(L, -3);