fix(engine): corregir figura 3D i text en real fullscreen

- Bug 2: moure shape_manager_->updateScreenSize() fora del bloc
  condicional SHAPE a les dues branques de toggleRealFullscreen(),
  de manera que ShapeManager sempre té les dimensions correctes quan
  s'activa una figura després d'entrar en fullscreen
- Bug text: passar base_screen_width_/height_ com a dimensions lògiques
  a ui_manager_->initialize() en recreateOffscreenTexture(), evitant
  que calculateFontSize() s'avaluï amb la resolució nativa de fullscreen

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

source/engine.cpp

@@ -927,6 +927,9 @@ void Engine::toggleRealFullscreen() {
                 // Actualizar tamaño de pantalla para boids (wrapping boundaries)
                 boid_manager_->updateScreenSize(current_screen_width_, current_screen_height_);
 
+                // Actualizar ShapeManager con nueva resolución (siempre, independientemente del modo actual)
+                shape_manager_->updateScreenSize(current_screen_width_, current_screen_height_);
+
                 // Actualizar AppLogo con nueva resolución
                 if (app_logo_) {
                     app_logo_->updateScreenSize(current_screen_width_, current_screen_height_);
@@ -960,6 +963,9 @@ void Engine::toggleRealFullscreen() {
         scene_manager_->updateScreenSize(current_screen_width_, current_screen_height_);
         scene_manager_->changeScenario(scene_manager_->getCurrentScenario(), current_mode_);
 
+        // Actualizar ShapeManager con resolución restaurada (siempre, independientemente del modo actual)
+        shape_manager_->updateScreenSize(current_screen_width_, current_screen_height_);
+
         // Actualizar AppLogo con resolución restaurada
         if (app_logo_) {
             app_logo_->updateScreenSize(current_screen_width_, current_screen_height_);
@@ -973,6 +979,23 @@ void Engine::toggleRealFullscreen() {
     }
 }
 
+void Engine::handlePostFXCycle() {
+    static constexpr float presets[5][3] = {
+        {1.5f, 0.0f, 0.0f}, {1.5f, 0.0f, 0.8f},
+        {1.5f, 1.0f, 0.0f}, {1.5f, 1.0f, 0.8f},
+        {0.0f, 0.0f, 0.0f}
+    };
+    static constexpr const char* names[5] = {
+        "PostFX: Vinyeta", "PostFX: Scanlines",
+        "PostFX: Cromàtica", "PostFX: Complet", "PostFX: Desactivat"
+    };
+    postfx_effect_mode_ = (postfx_effect_mode_ + 1) % 5;
+    postfx_uniforms_.vignette_strength = presets[postfx_effect_mode_][0];
+    postfx_uniforms_.chroma_strength   = presets[postfx_effect_mode_][1];
+    postfx_uniforms_.scanline_strength = presets[postfx_effect_mode_][2];
+    showNotificationForAction(names[postfx_effect_mode_]);
+}
+
 void Engine::toggleIntegerScaling() {
     // Solo permitir cambio si estamos en modo fullscreen normal (F3)
     if (!fullscreen_enabled_) {
@@ -1310,11 +1333,21 @@ void Engine::recreateOffscreenTexture() {
                                      SDL_GPU_TEXTUREFORMAT_R8G8B8A8_UNORM);
     }
 
-    // Recreate software surface to match new screen size
+    // Recreate renderer de software (DESTRUIR renderer PRIMER, després surface)
+    if (ui_renderer_) { SDL_DestroyRenderer(ui_renderer_); ui_renderer_ = nullptr; }
+    if (ui_surface_)  { SDL_DestroySurface(ui_surface_);   ui_surface_  = nullptr; }
+    ui_surface_ = SDL_CreateSurface(current_screen_width_, current_screen_height_, SDL_PIXELFORMAT_RGBA32);
     if (ui_surface_) {
-        SDL_DestroySurface(ui_surface_);
+        ui_renderer_ = SDL_CreateSoftwareRenderer(ui_surface_);
-        ui_surface_ = SDL_CreateSurface(current_screen_width_, current_screen_height_,
+    }
-                                         SDL_PIXELFORMAT_RGBA32);
+    // Re-inicialitzar components UI amb nou renderer
+    if (ui_renderer_ && ui_manager_) {
+        ui_manager_->initialize(ui_renderer_, theme_manager_.get(),
+                                current_screen_width_, current_screen_height_,  // physical
+                                base_screen_width_, base_screen_height_);        // logical (font size based on base)
+    }
+    if (ui_renderer_ && app_logo_) {
+        app_logo_->initialize(ui_renderer_, current_screen_width_, current_screen_height_);
     }
 }