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/Routes/RouteDetail.tsx

@@ -982,7 +982,7 @@ export default function RouteDetail() {
           </Collapsible>
 
           <div className={styles.tapModalFooter}>
-            <Button variant="secondary" onClick={() => setTapModalOpen(false)}>Cancel</Button>
+            <Button variant="ghost" onClick={() => setTapModalOpen(false)}>Cancel</Button>
             <Button variant="primary" onClick={saveTap} disabled={!tapName || !tapProcessor || !tapExpression}>Save</Button>
           </div>
         </div>
@@ -998,6 +998,7 @@ export default function RouteDetail() {
         confirmText={deletingTap?.attributeName ?? ''}
         confirmLabel="Delete"
         variant="danger"
+        loading={updateConfig.isPending}
       />
     </div>
   );