Show last-found location and time on the object card

Surfaces last_seen_location/last_seen_at (recorded by inventory
audit scans) on both the admin edit page and the public QR-scan
detail page, so it's visible without having to check the audit list.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/pages/admin/ObjectFormPage.tsx

@@ -122,6 +122,13 @@ export function ObjectFormPage() {
     <div className="mx-auto max-w-lg space-y-6">
       <h1 className="text-xl font-semibold">{isEditing ? 'Изменить объект' : 'Новый объект'}</h1>
 
+      {object?.last_seen_at && (
+        <p className="text-sm text-slate-500 dark:text-slate-400">
+          Последний раз найден{object.last_seen_location ? `: ${object.last_seen_location}` : ''} ·{' '}
+          {new Date(object.last_seen_at).toLocaleString('ru-RU', { dateStyle: 'medium', timeStyle: 'short' })}
+        </p>
+      )}
+
       <form onSubmit={handleSubmit(onSubmit)} className="space-y-4">
         <div className="space-y-1">
           <label className="text-sm font-medium">Инвентарный номер</label>

frontend/src/pages/public/ObjectDetailPage.tsx

@@ -23,6 +23,12 @@ export function ObjectDetailPage() {
       <div>
         <h1 className="text-2xl font-semibold text-slate-900 dark:text-slate-100">{object.name}</h1>
         <p className="text-sm text-slate-500 dark:text-slate-400">Инв. номер: {object.inventory_number}</p>
+        {object.last_seen_at && (
+          <p className="text-sm text-slate-500 dark:text-slate-400">
+            Последний раз найден{object.last_seen_location ? `: ${object.last_seen_location}` : ''} ·{' '}
+            {new Date(object.last_seen_at).toLocaleString('ru-RU', { dateStyle: 'medium', timeStyle: 'short' })}
+          </p>
+        )}
       </div>
       {object.description && (
         <p className="whitespace-pre-wrap text-slate-700 dark:text-slate-300">{object.description}</p>