migrated channel messages to jotai state (same as chat)

src/stores/channel.tsx

@@ -1,4 +1,11 @@
+import { atom } from 'jotai';
 import { atomWithReset } from 'jotai/utils';
 
 // channel reply id
 export const channelReplyAtom = atomWithReset({ id: null, pubkey: null, content: null });
+// channel messages
+export const channelMessagesAtom = atomWithReset([]);
+export const sortedChannelMessagesAtom = atom((get) => {
+  const messages = get(channelMessagesAtom);
+  return messages.sort((x: { created_at: number }, y: { created_at: number }) => x.created_at - y.created_at);
+});