feat(message): support group avatar in navigation and chat screen

Pass group avatar through notification extras, navigation hrefs, and
route parameters. Update ChatScreen to resolve group information
(ID, name, and avatar) by prioritizing route parameters (e.g., from
push notifications) and falling back to conversation data from the
MessageManager.

- Update `NotificationBootstrap` to include `groupAvatar` in query params
- Update `hrefChat` to support `groupAvatar`
- Refactor `useChatScreen` to use `effectiveGroupId`, `effectiveGroupName`,
  and `effectiveGroupAvatar`
- Ensure `MessageManager` fetches conversation details if missing when
  activating a conversation
- Update `MessageListScreen` to pass `groupAvatar` during navigation

src/stores/message/MessageManager.ts

@@ -344,6 +344,11 @@ class MessageManager {
     }
 
     const task = (async () => {
+      // 确保会话数据在 store 中（JPUSH 通知进入时 store 可能还没有此会话）
+      const store = useMessageStore.getState();
+      if (!store.getConversation(normalizedId)) {
+        await this.fetchConversationDetail(normalizedId);
+      }
       await this.fetchMessages(normalizedId);
     })();
     this.activatingConversationTasks.set(normalizedId, task);