fix: define global toast utility in app-init

- Added window.toast() in app-init.js so workshop/customers/inventory pages can use it.

- Bumped app-init.js cache version on all templates.

pos/templates/supplier_catalog.html

@@ -126,7 +126,7 @@
     </div>
   </div>
 
-  <script src="/pos/static/js/app-init.js" defer></script>
+  <script src="/pos/static/js/app-init.js?v=2" defer></script>
   <script src="/pos/static/js/sidebar.js?v=36" defer></script>
   <script src="/pos/static/js/supplier_catalog.js?v=33" defer></script>
   <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>