refactor(core/rendering): esborrar structs d'extensions GIF no usats (DEAD-09)

gif.hpp declarava Extension, GraphicControlExtension, ApplicationExtension
i PlaintextExtension com a tipus "empaquetats" per a llegir blocs del
stream GIF. El parser a gif.cpp, però, processa els bytes cru (avança
el punter i llig block_size + sub-blocs manualment) sense instanciar-los
mai. Les struct eren code pattern orientat a reus futurs que no va
arribar a materialitzar-se.

Build + smoke 5s xvfb OK (exit 124).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/audit-core-rendering.md

@@ -102,7 +102,7 @@ Los IDs se mantienen estables una vez asignados. Cada entrada apunta al(los) fic
 | DEAD-06 | `sprite.hpp:12`, `moving_sprite.hpp:13` | ctors default sin callers | Menor | WONTFIX | usats transitivament pel ctor de `AnimatedSprite` (base-class-construction) |
 | DEAD-07 | `animated_sprite.hpp:30` | `getCurrentAnimationSize()` sin callers | Menor | DONE | esborrat |
 | DEAD-08 | `surface.hpp:61` | `getSurfaceData()` sin callers externos | Menor | DONE | esborrat |
-| DEAD-09 | `gif.hpp:45-65` | `Extension`, `ApplicationExtension`, `PlaintextExtension`, `GraphicControlExtension` no instanciados | Menor | PENDING | borrar |
+| DEAD-09 | `gif.hpp:45-65` | `Extension`, `ApplicationExtension`, `PlaintextExtension`, `GraphicControlExtension` no instanciados | Menor | DONE | esborrats (el parser processa bytes cru) |
 | DEAD-10 | `sprite.cpp:47-49` | `Sprite::update` hook no invocado | Menor | DONE | inlined buit al header (resol PATCH-04) |
 
 ## 7. Violaciones de convenciones del proyecto
@@ -128,4 +128,5 @@ Los IDs se mantienen estables una vez asignados. Cada entrada apunta al(los) fic
 - `029907d` — COUP-02a: `Screen` desacoblat de `SDL3GPUShader` via `makeDefaultShaderBackend()`
 - `81fe826` — COUP-02b (= COUP-03): `Surface` usa `Rendering::activeCanvas()` en lloc de `Screen::get()`
 - `b51109e` — DEAD-01 + DEAD-02 + DEAD-03: esborrats mètodes mort de `Text`
-- `<pendent>` — DEAD-04/05/07/08/10 + PATCH-04: neteja mort a `Sprite`/`AnimatedSprite`/`Surface` + `Sprite::update` inline
+- `597402a` — DEAD-04/05/07/08/10 + PATCH-04: neteja mort a `Sprite`/`AnimatedSprite`/`Surface` + `Sprite::update` inline
+- `<pendent>` — DEAD-09: esborrats structs d'extensions GIF no usats

source/core/rendering/gif.hpp

@@ -42,28 +42,6 @@ namespace GIF {
         int len;
     };
 
-    struct Extension {
-        uint8_t extension_code;
-        uint8_t block_size;
-    };
-
-    struct GraphicControlExtension {
-        uint8_t fields;
-        uint16_t delay_time;
-        uint8_t transparent_color_index;
-    };
-
-    struct ApplicationExtension {
-        uint8_t application_id[8];
-        uint8_t version[3];
-    };
-
-    struct PlaintextExtension {
-        uint16_t left, top, width, height;
-        uint8_t cell_width, cell_height;
-        uint8_t foreground_color, background_color;
-    };
-
     class Gif {
        public:
         // Descompone (uncompress) el bloque comprimido usando LZW.