fix: resolve chat current user from auth store instead of hardcoded participants[0]

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

@@ -10,12 +10,14 @@ import { Input } from "@/components/ui/input"
 import { ScrollArea } from "@/components/ui/scroll-area"
 import { mockChatMessages, mockChatSessions } from "@/lib/mock-data"
 import { cn } from "@/lib/utils"
+import { useAuthStore } from "@/store/auth"
 
 export default function ChatDetailPage({ params }: { params: Promise<{ id: string }> }) {
   const { id } = use(params)
   const session = mockChatSessions.find((s) => s.id === id)
   const messages = mockChatMessages.filter((m) => m.sessionId === id)
   const [input, setInput] = useState("")
+  const { user } = useAuthStore()
 
   if (!session) {
     return (
@@ -25,8 +27,8 @@ export default function ChatDetailPage({ params }: { params: Promise<{ id: strin
     )
   }
 
-  const other = session.participants[1]
-  const currentUserId = session.participants[0].id
+  const currentUserId = user?.id ?? session.participants[0].id
+  const other = session.participants.find((p) => p.id !== currentUserId) ?? session.participants[1]
 
   return (
     <div className="flex flex-col h-[calc(100vh-3.5rem)]">