refactor: useOnlineCount 重构为 useOnlineUsers，DictMessage 重命名为 DictChangeMessage

src/composables/sse/useOnlineCount.ts

@@ -1,65 +0,0 @@
-import { ref, onMounted, getCurrentInstance } from "vue";
-import { useSse } from "./useSse";
-
-let globalInstance: ReturnType<typeof createOnlineCountComposable> | null = null;
-
-function createOnlineCountComposable() {
-  const onlineUserCount = ref(0);
-  const lastUpdateTime = ref(0);
-
-  const sse = useSse();
-
-  let unsubscribe: (() => void) | null = null;
-
-  // 处理在线人数变更消息
-  const handleOnlineCountMessage = (count: number) => {
-    if (!Number.isFinite(count) || count < 0) return;
-    onlineUserCount.value = count;
-    lastUpdateTime.value = Date.now();
-  };
-
-  const initialize = () => {
-    sse.connect();
-    unsubscribe = sse.on("online-count", handleOnlineCountMessage);
-  };
-
-  const cleanup = () => {
-    if (unsubscribe) {
-      unsubscribe();
-      unsubscribe = null;
-    }
-    onlineUserCount.value = 0;
-    lastUpdateTime.value = 0;
-  };
-
-  return {
-    onlineUserCount: readonly(onlineUserCount),
-    lastUpdateTime: readonly(lastUpdateTime),
-    isConnected: sse.isConnected,
-    connectionState: sse.connectionState,
-    initialize,
-    cleanup,
-  };
-}
-
-/**
- * 在线用户计数组合式函数（单例模式）
- */
-export function useOnlineCount(options: { autoInit?: boolean } = {}) {
-  const { autoInit = true } = options;
-
-  if (!globalInstance) {
-    globalInstance = createOnlineCountComposable();
-  }
-
-  const instance = getCurrentInstance();
-  if (autoInit && instance) {
-    onMounted(() => {
-      if (!globalInstance!.isConnected.value) {
-        globalInstance!.initialize();
-      }
-    });
-  }
-
-  return globalInstance;
-}