refactor(auth): support async deferred actions for login gating

Allow deferred login actions to return promises and execute them safely without violating lint rules. Also initialize order detail timer state without impure render-time Date.now calls so React hook purity checks pass.

lib/use-require-auth.ts

@@ -9,9 +9,9 @@ export function useRequireAuth() {
   const openLoginDialog = useLoginDialogStore((s) => s.openLoginDialog)
 
   const requireAuth = useCallback(
-    (action: () => void) => {
+    (action: () => void | Promise<void>) => {
       if (isAuthenticated) {
-        action()
+        void action()
       } else {
         openLoginDialog(action)
       }