feat(title): paleta neon synthwave per element a l'escena de títol

source/core/graphics/starfield.cpp

@@ -94,7 +94,7 @@ namespace Graphics {
                 .rotation_euler = Vec3{.x = star.rot_phase_x, .y = star.rot_phase_y, .z = 0.0F},
                 .scale = star.scale,
             };
-            drawWireframe(renderer_, *camera_, octahedron_, TRANSFORM, computeBrightness(star));
+            drawWireframe(renderer_, *camera_, octahedron_, TRANSFORM, computeBrightness(star), color_);
         }
     }
 
@@ -102,4 +102,8 @@ namespace Graphics {
         brightness_mult_ = std::max(0.0F, multiplier);
     }
 
+    void Starfield::setColor(SDL_Color color) {
+        color_ = color;
+    }
+
 }  // namespace Graphics

source/core/graphics/starfield.hpp

@@ -8,6 +8,8 @@
 
 #pragma once
 
+#include <SDL3/SDL.h>
+
 #include <vector>
 
 #include "core/graphics/camera3d.hpp"
@@ -25,6 +27,7 @@ namespace Graphics {
         void draw() const;
 
         void setBrightness(float multiplier);
+        void setColor(SDL_Color color);
 
        private:
         struct Star {
@@ -45,6 +48,7 @@ namespace Graphics {
         std::vector<Star> stars_;
         Mesh3D octahedron_;
         float brightness_mult_{1.0F};
+        SDL_Color color_{.r = 0, .g = 0, .b = 0, .a = 0};  // alpha=0 → usa color global
 
         // Volum de spawn / regeneració en l'espai 3D.
         static constexpr float Z_NEAR_RESPAWN = 5.0F;  // Si Z < aquest valor → regenera