unify Weapon and StationWeapon components

src/lib/sim/Building.h

@@ -56,17 +56,6 @@ struct ConstructionSite
     std::optional<ShipLayoutConfig> shipLayout;
 };
 
-// Weapon state for stationary structures (defence stations).
-// Distinct from Ship::Weapon; stations have no movement intent.
-struct StationWeapon
-{
-    float damage;
-    float range;
-    float fireRateHz;
-    float cooldownTicks;
-    std::optional<entt::entity> currentTarget;
-};
-
 // A fully constructed, operational building.
 struct Building
 {
@@ -90,3 +79,4 @@ struct Building
     // Module layout for shipyards (REQ-MOD-LAYOUT).
     std::optional<ShipLayoutConfig> shipLayout;
 };
+