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

app/(order)/chat/[id]/page.tsx

@@ -28,8 +28,8 @@ export default function ChatDetailPage({ params }: { params: Promise<{ id: strin
     )
   }
 
-  const currentUserId = user?.id ?? session.participants[0].id
-  const other = session.participants.find((p) => p.id !== currentUserId) ?? session.participants[1]
+  const userId = user?.id ?? session.participants[0].id
+  const other = session.participants.find((p) => p.id !== userId) ?? session.participants[1]
 
   return (
     <div className="flex flex-col h-[calc(100vh-3.5rem)]">
@@ -69,7 +69,7 @@ export default function ChatDetailPage({ params }: { params: Promise<{ id: strin
                 </div>
               )
             }
-            const isMine = msg.senderId === currentUserId
+            const isMine = msg.senderId === userId
             return (
               <div key={msg.id} className={cn("flex gap-2", isMine && "flex-row-reverse")}>
                 <Avatar className="h-8 w-8 shrink-0">
@@ -107,13 +107,11 @@ export default function ChatDetailPage({ params }: { params: Promise<{ id: strin
               const text = input.trim()
               if (!text) return
 
-              const sender = session.participants.find(
-                (participant) => participant.id === currentUserId,
-              )
+              const sender = session.participants.find((participant) => participant.id === userId)
               sendTextMessage(
                 session.id,
                 {
-                  id: currentUserId,
+                  id: userId,
                   name: sender?.name ?? user?.nickname ?? "",
                   avatar: sender?.avatar ?? user?.avatar ?? "",
                 },