refactor: consolidar Ship::isAlive/isHit/isActive en isActive()

Els tres mètodes retornaven el mateix bool a partir d'is_hit_:
  isActive() = !is_hit_   (override de Entity)
  isAlive()  = !is_hit_
  isHit()    =  is_hit_

Eren tres formes diferents de preguntar el mateix, repartides sense
criteri pels call-sites (collision_system, game_scene). Conservem
isActive() perquè és l'override polimòrfic d'Entity i esborrem els
altres dos. Actualitzats els 5 call-sites externs.

Hallazgo #11 de CODE_REVIEW.md.

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

source/game/entities/ship.hpp

@@ -34,9 +34,7 @@ class Ship : public Entities::Entity {
         return !is_hit_ && invulnerable_timer_ <= 0.0F;
     }
 
-        // Getters (API pública sin cambios)
-        [[nodiscard]] auto isAlive() const -> bool { return !is_hit_; }
-        [[nodiscard]] auto isHit() const -> bool { return is_hit_; }
+    // Getters
     [[nodiscard]] auto isInvulnerable() const -> bool { return invulnerable_timer_ > 0.0F; }
     // Velocidad como vector cartesiano (ahora viene directa del body_).
     [[nodiscard]] auto getVelocityVector() const -> Vec2 { return body_.velocity; }

source/game/scenes/game_scene.cpp

@@ -573,11 +573,11 @@ void GameScene::drawInitHudState() {
         Systems::InitHud::drawScoreboardAnimated(text_, buildScoreboard(), score_progress);
     }
 
-    if (ship1_progress > 0.0F && match_config_.jugador1_actiu && !ships_[0].isHit()) {
+    if (ship1_progress > 0.0F && match_config_.jugador1_actiu && ships_[0].isActive()) {
         ships_[0].draw();
     }
 
-    if (ship2_progress > 0.0F && match_config_.jugador2_actiu && !ships_[1].isHit()) {
+    if (ship2_progress > 0.0F && match_config_.jugador2_actiu && ships_[1].isActive()) {
         ships_[1].draw();
     }
 }
@@ -820,7 +820,7 @@ void GameScene::fireBullet(uint8_t player_id) {
     if (hit_timer_per_player_[player_id] > 0.0F) {
         return;
     }
-    if (!ships_[player_id].isAlive()) {
+    if (!ships_[player_id].isActive()) {
         return;
     }
 

source/game/systems/collision_system.cpp

@@ -10,7 +10,7 @@
 
 namespace Systems::Collision {
 
-void detectBulletEnemy(Context& ctx) {
+    void detectBulletEnemy(Context& ctx) {
         constexpr float AMPLIFIER = Defaults::Game::COLLISION_BULLET_ENEMY_AMPLIFIER;
         constexpr float VELOCITAT_EXPLOSIO = 80.0F;  // px/s (explosión suau)
 
@@ -44,9 +44,15 @@ void detectBulletEnemy(Context& ctx) {
                 // 2. Destruir enemy + crear explosión (debris hereda color del enemy)
                 SDL_Color enemy_color{};
                 switch (enemy.getType()) {
-                case EnemyType::PENTAGON:  enemy_color = Defaults::Palette::PENTAGON;  break;
-                case EnemyType::QUADRAT:   enemy_color = Defaults::Palette::QUADRAT;   break;
-                case EnemyType::MOLINILLO: enemy_color = Defaults::Palette::MOLINILLO; break;
+                    case EnemyType::PENTAGON:
+                        enemy_color = Defaults::Palette::PENTAGON;
+                        break;
+                    case EnemyType::QUADRAT:
+                        enemy_color = Defaults::Palette::QUADRAT;
+                        break;
+                    case EnemyType::MOLINILLO:
+                        enemy_color = Defaults::Palette::MOLINILLO;
+                        break;
                 }
                 enemy.destruir();
                 Vec2 vel_enemic = enemy.getVelocityVector();
@@ -61,23 +67,22 @@ void detectBulletEnemy(Context& ctx) {
                     enemy.getRotationDelta(),
                     0.0F,  // sin herencia visual
                     Defaults::Sound::EXPLOSION,
-                enemy_color
-            );
+                    enemy_color);
 
                 // 3. Desactivar bullet (solo destruye 1 enemy)
                 bullet.desactivar();
                 break;
             }
         }
-}
+    }
 
-void detectShipEnemy(Context& ctx) {
+    void detectShipEnemy(Context& ctx) {
         constexpr float AMPLIFIER = Defaults::Game::COLLISION_SHIP_ENEMY_AMPLIFIER;
 
         for (uint8_t i = 0; i < 2; i++) {
             // Skip si ya tocado / muerto / invulnerable
             if (ctx.hit_timer_per_player[i] > 0.0F ||
-            !ctx.ships[i].isAlive() ||
+                !ctx.ships[i].isActive() ||
                 ctx.ships[i].isInvulnerable()) {
                 continue;
             }
@@ -92,9 +97,9 @@ void detectShipEnemy(Context& ctx) {
                 }
             }
         }
-}
+    }
 
-void detectBulletPlayer(Context& ctx) {
+    void detectBulletPlayer(Context& ctx) {
         if (!Defaults::Game::FRIENDLY_FIRE_ENABLED) {
             return;
         }
@@ -109,7 +114,7 @@ void detectBulletPlayer(Context& ctx) {
 
             for (uint8_t player_id = 0; player_id < 2; player_id++) {
                 if (ctx.hit_timer_per_player[player_id] > 0.0F ||
-                !ctx.ships[player_id].isAlive() ||
+                    !ctx.ships[player_id].isActive() ||
                     ctx.ships[player_id].isInvulnerable()) {
                     continue;
                 }
@@ -139,12 +144,12 @@ void detectBulletPlayer(Context& ctx) {
                 break;  // Una bullet solo impacta una vez por frame
             }
         }
-}
+    }
 
-void detectAll(Context& ctx) {
+    void detectAll(Context& ctx) {
         detectBulletEnemy(ctx);
         detectShipEnemy(ctx);
         detectBulletPlayer(ctx);
-}
+    }
 
 }  // namespace Systems::Collision