fix(frontend): require guildId for channel creation and fallback from channel list

src/pages/ChatPage.tsx

@@ -10,7 +10,7 @@ type MessageItem = {
   isDeleted?: boolean
 }
 
-type GuildChannel = { id: string; name: string }
+type GuildChannel = { id: string; name: string; guildId?: string }
 type GuildRecord = { id: string; name: string }
 type GuildMember = { id: string; userId: string; guildId: string; status: string }
 
@@ -69,6 +69,7 @@ export default function ChatPage() {
       })
       const list = Array.isArray(res.data) ? (res.data as GuildChannel[]) : []
       setChannels(list)
+      if (!guildDbId && list[0]?.guildId) setGuildDbId(list[0].guildId)
       if (!selectedChannelId && list.length) setSelectedChannelId(list[0].id)
     } catch {
       setError('Failed to load channels')
@@ -129,10 +130,13 @@ export default function ChatPage() {
 
   async function createChannel() {
     if (!guild || !guildToken || !newChannelName.trim()) return
+    if (!guildDbId) {
+      setError('Cannot create channel: guildId is missing')
+      return
+    }
     setError('')
     try {
-      const payload = guildDbId ? { name: newChannelName.trim(), guildId: guildDbId } : { name: newChannelName.trim() }
-      const res = await guildApi().post('/channels', payload)
+      const res = await guildApi().post('/channels', { name: newChannelName.trim(), guildId: guildDbId })
       const createdId = res.data?.id as string | undefined
       setNewChannelName('')
       await loadChannels()