feat(teams): fix checkbox multi-select and improve batch operations UI

- Fix checkbox binding using :model-value instead of :checked
- Change selectedIds from Set to reactive array for proper Vue reactivity
- Move batch refresh/delete buttons to top bar (matching CardKeysPage layout)
- Buttons show selection count like 'Refresh (2)' when items selected
- Swap position of 'Add Team' and 'Random Invite' buttons
- Remove unused isIndeterminate computed property

backend/internal/static/dist/assets/circle-x-C8-4gjQR.js

@@ -0,0 +1 @@
+import{c}from"./index-B0FmaMuw.js";const r=c("circle-x",[["circle",{cx:"12",cy:"12",r:"10",key:"1mglay"}],["path",{d:"m15 9-6 6",key:"1uzhvr"}],["path",{d:"m9 9 6 6",key:"z0biqf"}]]);export{r as C};