step 6.3: done

src/services/shopService.js

@@ -148,6 +148,19 @@ function sellItem(characterId, itemId, quantity) {
   const item = s.itemById.get(itemId);
   if (!item) throw new AppError('NOT_FOUND', 'Item not found.', 404);
 
+  // Find inventory rows for this (character, item).
+  const rows = s.inventoryRows.all(characterId, itemId, 1);
+  if (rows.length === 0) {
+    throw new AppError('NOT_FOUND', 'Item not in inventory.', 404);
+  }
+
+  // Reject if any row is equipped.
+  for (const row of rows) {
+    if (row.equipped_slot !== null) {
+      throw new AppError('VALIDATION_ERROR', 'Unequip the item before selling.', 400);
+    }
+  }
+
   if (item.type !== 'material') {
     throw new AppError('VALIDATION_ERROR', 'Only materials can be sold.', 400);
   }
@@ -161,12 +174,6 @@ function sellItem(characterId, itemId, quantity) {
     sellPrice = Math.max(1, Math.floor(defaultRate * ch.level / item.min_level));
   }
 
-  // Find inventory rows for this (character, item).
-  const rows = s.inventoryRows.all(characterId, itemId, 1);
-  if (rows.length === 0) {
-    throw new AppError('NOT_FOUND', 'Item not in inventory.', 404);
-  }
-
   // Calculate how many we can actually sell from available rows.
   let remaining = quantity;
   const sales = []; // { rowId, qty, sellPrice }