fix: prefill item names in lootbox pool entries when editing

Resolve ITEM-type pool entry names from the API when loading an
existing lootbox for editing, so the ItemSearchPicker displays
the selected item instead of showing an empty default.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

panel/src/pages/ItemStudio.tsx

@@ -1177,9 +1177,46 @@ export function ItemStudio({
     setError(null);
 
     get<FullItem>(`/api/items/${editItemId}`)
-      .then((item) => {
+      .then(async (item) => {
         if (cancelled) return;
         const newDraft = draftFromItem(item);
+
+        // Resolve item names for ITEM-type loot pool entries
+        const itemIdsToResolve = new Set<number>();
+        for (const eff of newDraft.effects) {
+          if (eff.kind === "LOOTBOX") {
+            for (const entry of eff.pool) {
+              if (entry.type === "ITEM" && entry.itemId) {
+                itemIdsToResolve.add(Number(entry.itemId));
+              }
+            }
+          }
+        }
+
+        if (itemIdsToResolve.size > 0) {
+          const resolved = await Promise.all(
+            [...itemIdsToResolve].map((id) =>
+              get<{ id: number; name: string; rarity: string }>(`/api/items/${id}`).catch(() => null)
+            )
+          );
+          const itemMap = new Map(
+            resolved.filter(Boolean).map((i) => [i!.id, i!])
+          );
+
+          for (const eff of newDraft.effects) {
+            if (eff.kind === "LOOTBOX") {
+              for (const entry of eff.pool) {
+                const info = itemMap.get(Number(entry.itemId));
+                if (info) {
+                  entry.selectedItemName = info.name;
+                  entry.selectedItemRarity = info.rarity;
+                }
+              }
+            }
+          }
+        }
+
+        if (cancelled) return;
         const newIconUrl = item.iconUrl ?? "";
         const newImageUrl = item.imageUrl ?? "";
         setDraft(newDraft);