refactor(auth): unify current user state usage across UI

components/post-comments.tsx

@@ -2,7 +2,7 @@
 
 import { Heart } from "lucide-react"
 import { useState } from "react"
-import { currentUser } from "@/lib/mock"
+import { generateId } from "@/lib/id"
 import type { Comment } from "@/lib/types"
 import { useRequireAuth } from "@/lib/use-require-auth"
 import { useAuthStore } from "@/store/auth"
@@ -32,14 +32,14 @@ export function PostComments({ initialComments, postId }: PostCommentsProps) {
           requireAuth(() => {
             const nextContent = content.trim()
             if (!nextContent) return
-            const author = user ?? currentUser
+            if (!user) return
             const createdAt = new Date().toISOString()
             setComments((prev) => [
               ...prev,
               {
-                id: `comment-${postId}-${createdAt}`,
+                id: generateId(`comment-${postId}`),
                 postId,
-                author,
+                author: user,
                 content: nextContent,
                 likeCount: 0,
                 liked: false,