fix(web): resolve React #310 hook order crash in MessageList

- move forwardTargets useMemo above conditional early return

- keep hooks call order stable after login/activeChat switch

web/src/components/MessageList.tsx

@@ -34,12 +34,6 @@ export function MessageList() {
 
   const messagesMap = useMemo(() => new Map(messages.map((m) => [m.id, m])), [messages]);
   const activeChat = chats.find((chat) => chat.id === activeChatId);
-
-  if (!activeChatId) {
-    return <div className="flex h-full items-center justify-center text-slate-300/80">Select a chat</div>;
-  }
-  const chatId = activeChatId;
-
   const forwardTargets = useMemo(() => {
     const q = forwardQuery.trim().toLowerCase();
     if (!q) return chats;
@@ -50,6 +44,11 @@ export function MessageList() {
     });
   }, [chats, forwardQuery]);
 
+  if (!activeChatId) {
+    return <div className="flex h-full items-center justify-center text-slate-300/80">Select a chat</div>;
+  }
+  const chatId = activeChatId;
+
   async function handleForward(targetChatId: number) {
     if (!forwardMessageId) return;
     setIsForwarding(true);