fix(inventory): refresh list, close modal, update badges after creating item

- Expose loadInventoryStats globally so inventory.js can call it after CRUD
- Fix token key: use pos_token (not access_token) to match auth scheme
- After successful POST /items: close modal, clear form inputs, reload stats
- Bump inventory.js cache-bust query param v3 -> v4

pos/templates/inventory.html

@@ -815,7 +815,7 @@
   <script src="/pos/static/js/pos-utils.js" defer></script>
   <script src="/pos/static/js/sidebar.js" defer></script>
   <script src="/pos/static/js/virtual-scroll.js" defer></script>
-  <script src="/pos/static/js/inventory.js?v=3" defer></script>
+  <script src="/pos/static/js/inventory.js?v=4" defer></script>
   <script src="/pos/static/js/offline-banner.js" defer></script>
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
@@ -823,9 +823,9 @@
   <script src="/pos/static/js/chat.js" defer></script>
   <script>
     // Load inventory stats for tab badges
-    (async function loadInventoryStats() {
+    async function loadInventoryStats() {
       try {
-        const token = localStorage.getItem('access_token');
+        const token = localStorage.getItem('pos_token');
         if (!token) return;
         const res = await fetch('/pos/api/inventory/stats', {
           headers: { 'Authorization': 'Bearer ' + token }
@@ -848,7 +848,9 @@
       } catch (e) {
         console.error('Failed to load inventory stats:', e);
       }
-    })();
+    }
+    window.loadInventoryStats = loadInventoryStats;
+    loadInventoryStats();
   </script>
 </body>
 </html>