feat(entities): derivar collision_radius del shape + scale/collision_factor al YAML

source/game/entities/ship.hpp

@@ -6,7 +6,6 @@
 
 #include <cstdint>
 
-#include "core/defaults.hpp"
 #include "core/entities/entity.hpp"
 #include "core/types.hpp"
 #include "game/entities/player_config.hpp"
@@ -30,10 +29,9 @@ class Ship : public Entities::Entity {
     // Override: Interfaz de Entity
     [[nodiscard]] auto isActive() const -> bool override { return !is_hit_; }
 
-    // Override: Interfaz de colisión
-    [[nodiscard]] auto getCollisionRadius() const -> float override {
-        return config_.physics.collision_radius;
-    }
+    // Override: Interfaz de colisión. Derivat al ctor del bounding_radius del
+    // shape carregat × scale × collision_factor.
+    [[nodiscard]] auto getCollisionRadius() const -> float override { return collision_radius_; }
     [[nodiscard]] auto isCollidable() const -> bool override {
         return !is_hit_ && invulnerable_timer_ <= 0.0F;
     }
@@ -73,6 +71,9 @@ class Ship : public Entities::Entity {
     // copy/move-assignment quan GameScene crea la nau real.
     PlayerConfig config_{};
 
+    // Radi de col·lisió derivat: shape.bounding_radius × shape.scale × shape.collision_factor.
+    float collision_radius_{0.0F};
+
     bool is_hit_{false};
     float invulnerable_timer_{0.0F};  // 0.0f = vulnerable, >0.0f = invulnerable