chore(item-history): move getAdminPocketBase import to top, drop unused PB type alias

Co-authored-by: Orca <help@stably.ai>

src/lib/server/item-history-service.ts

@@ -10,6 +10,7 @@
  * price-list backfill) can reuse them. Keep them PB-free.
  */
 
+import { getAdminPocketBase } from "@/lib/server/pocketbase-admin";
 import type {
   ItemHistory,
   ItemHistoryMatch,
@@ -125,9 +126,6 @@ export function isValidPrice(v: number | null | undefined): boolean {
 }
 
 // ─── PB-backed service ───────────────────────────────────────────────
-import { getAdminPocketBase } from "@/lib/server/pocketbase-admin";
-
-type PB = Awaited<ReturnType<typeof getAdminPocketBase>>;
 
 /** Fetch the deterministic item history for a `quote_items` row. */
 export async function getItemHistory(itemId: string): Promise<ItemHistory> {