fix: table sorting blocked by pointerEvents:none during loading

Root cause: useListData set loading=true on every refetch, and all 4
admin list pages (offers, orders, invoices, projects) applied
pointerEvents:'none' while loading — blocking all clicks including
sort column headers.

Fix: removed setLoading(true) from refetch (matching PHP behavior)
and removed pointerEvents from all list page cards. Opacity fade
kept as visual feedback.

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

src/admin/hooks/useListData.ts

@@ -41,7 +41,6 @@ export default function useListData<T = unknown>(
     const controller = new AbortController()
     abortRef.current = controller
 
-    setLoading(true)
     try {
       const params = new URLSearchParams({
         page: String(page),