Derive ship scrap drop from threat

src/lib/ecs/system/ShipSystem.cpp

@@ -1,6 +1,8 @@
 #include "ShipSystem.h"
 
+#include <algorithm>
 #include <cassert>
+#include <cmath>
 #include <map>
 #include <stdexcept>
 #include <utility>
@@ -26,7 +28,9 @@
 #include "SalvagerComponent.h"
 #include "SelectedBehaviorComponent.h"
 #include "SensorRangeComponent.h"
+#include "ShipIdentityComponent.h"
 #include "StandbyBehavior.h"
+#include "ThreatCostCalculator.h"
 #include "Tick.h"
 #include "tracing.h"
 #include "WeaponComponent.h"
@@ -103,6 +107,16 @@ entt::entity ShipSystem::spawn(const std::string& schematicId, int level,
     const std::vector<PlacedModule>& modules =
         layout.has_value() ? layout->placedModules : def->defaultModules;
 
+    // Derive the scrap dropped on destruction from the ship's as-built threat cost
+    // (REQ-RES-SCRAP-DROP): round(threat * scrap_per_threat), floored at 1 for any
+    // ship with threat > 0. Computed once here since threat is level-independent.
+    const double threatCost = calculateShipThreatCost(m_config.threatCosts, m_config,
+                                                      schematicId, modules);
+    const int scrapDrop = threatCost > 0.0
+        ? std::max(1, static_cast<int>(std::lround(threatCost * m_config.world.scrapPerThreat)))
+        : 0;
+    m_admin.get<ShipIdentityComponent>(entity).scrapDrop = scrapDrop;
+
     // --- Pass 1: create capability child entities ----------------------------
     std::vector<entt::entity> weaponChildren;
     std::vector<entt::entity> salvageChildren;