fix(hud): correct cost calculation using weapon decay from Nexus API

- Use actual weapon decay (PEC) from API instead of broken DPP calculation
- Add decay and ammo_burn to weapon stats passed from Gear Selector
- Cost per shot = decay (in PEC) / 100 = PED

ui/gear_selector.py

@@ -292,8 +292,13 @@ class GearSelectorDialog(QDialog):
             if self.gear_type == "weapon":
                 w = self.selected_gear
                 self.gear_selected.emit("weapon", w.name, {
-                    'id': w.id, 'item_id': w.item_id, 'dpp': float(w.dpp),
-                    'cost_per_hour': float(w.cost_per_hour), 'total_damage': float(w.total_damage),
+                    'id': w.id,
+                    'item_id': w.item_id,
+                    'dpp': float(w.dpp),
+                    'cost_per_hour': float(w.cost_per_hour),
+                    'total_damage': float(w.total_damage),
+                    'decay': float(w.decay) if w.decay else 0,
+                    'ammo_burn': w.ammo_burn or 0,
                 })
             elif self.gear_type == "armor":
                 a = self.selected_gear

ui/main_window.py

@@ -1006,17 +1006,15 @@ class MainWindow(QMainWindow):
             damage = event.data.get('damage', 0)
             self.hud.on_damage_dealt(float(damage))
             
-            # Estimate cost per shot based on weapon stats
+            # Track weapon decay cost per shot
+            # Only count as one shot fired per damage event
             if self._selected_weapon_stats:
-                dpp = self._selected_weapon_stats.get('dpp', 0)
-                if dpp and dpp > 0:
-                    # Cost per shot in PEC = damage / DPP
-                    # Convert to Decimal for precision
+                # Get decay per shot from weapon stats (in PEC)
+                decay = self._selected_weapon_stats.get('decay', 0)
+                if decay:
                     from decimal import Decimal
-                    damage_dec = Decimal(str(damage))
-                    dpp_dec = Decimal(str(dpp))
-                    cost_pec = damage_dec / dpp_dec
-                    cost_ped = cost_pec / Decimal('100')  # Convert to PED
+                    # Convert PEC to PED
+                    cost_ped = Decimal(str(decay)) / Decimal('100')
                     self.hud.update_cost(cost_ped)
         
         def on_critical_hit(event):