fix: standardize button order, add confirmation dialogs for destructive actions

- Fix Cancel|Save order and add primary/loading props (AppConfigDetailPage)
- Add AlertDialog before stopping deployments (AppsTab)
- Add ConfirmDialog before deleting taps (TapConfigModal)
- Add AlertDialog before killing queries with toast feedback (DatabaseAdminPage)
- Add AlertDialog before removing roles from users (UsersTab)
- Standardize Cancel button to variant="ghost" (TapConfigModal, RouteDetail)
- Add loading prop to ConfirmDialogs (OidcConfigPage, RouteDetail)

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

ui/src/pages/Admin/OidcConfigPage.tsx

@@ -261,6 +261,7 @@ export default function OidcConfigPage() {
           onConfirm={handleDelete}
           message="Delete OIDC configuration? All users signed in via OIDC will lose access."
           confirmText="delete oidc"
+          loading={saving}
         />
       </section>
     </div>