feat: 添加环境变量示例，更新样式和依赖，增强全局状态管理

stores/state.ts

@@ -0,0 +1,51 @@
+import type { LocalMessage, VisitorRole } from "~/types";
+
+export const useGState = defineStore("global_state", () => {
+  const currentRole = ref<VisitorRole>("stu");
+  const botName = computed(() => {
+    switch (currentRole.value) {
+      case "stu":
+        return "AI 辅导员";
+      case "tea":
+        return "AI 教研专家";
+      case "fans":
+        return "校园百事通";
+      default:
+        return "AI 智慧校园";
+    }
+  });
+
+  const setCurrentRole = (role: VisitorRole) => {
+    currentRole.value = role;
+  };
+
+  const messagesByRole = ref<Record<VisitorRole, LocalMessage[]>>({
+    stu: [],
+    tea: [],
+    fans: [],
+  });
+  const messages = computed({
+    get: () => messagesByRole.value[currentRole.value],
+    set: (value: LocalMessage[]) => {
+      messagesByRole.value[currentRole.value] = value;
+    },
+  });
+
+  const insertOrUpdateMessage = (message: LocalMessage) => {
+    const index = messages.value.findIndex((m) => m.id === message.id);
+    if (index >= 0) {
+      messages.value.splice(index, 1, message);
+    } else {
+      messages.value.push(message);
+    }
+  };
+
+  return {
+    currentRole,
+    botName,
+    setCurrentRole,
+    messagesByRole,
+    messages,
+    insertOrUpdateMessage,
+  };
+});