fix: unify main tab navigation behavior

src/utils/main-tabbar.ts

@@ -0,0 +1,39 @@
+import Taro from "@tarojs/taro";
+import type { TabbarItem } from "../components/bottom-tabbar";
+
+type MainTabKey = "home" | "report" | "assistant" | "message" | "mine";
+
+const mainTabRoutes: Partial<Record<MainTabKey, string>> = {
+  home: "/pages/index/index",
+  report: "/pages/report/index",
+  message: "/pages/message/index",
+  mine: "/pages/mine/index"
+};
+
+export function createMainTabItems(activeKey: MainTabKey): TabbarItem[] {
+  return [
+    { key: "home", label: "首页", active: activeKey === "home" },
+    { key: "report", label: "报告", active: activeKey === "report" },
+    { key: "assistant", label: "小e", active: activeKey === "assistant" },
+    { key: "message", label: "消息", active: activeKey === "message", badge: true },
+    { key: "mine", label: "我的", active: activeKey === "mine" }
+  ];
+}
+
+export function handleMainTabNavigation(item: TabbarItem, activeKey: MainTabKey) {
+  if (item.key === activeKey) {
+    return;
+  }
+
+  const route = mainTabRoutes[item.key as MainTabKey];
+
+  if (route) {
+    Taro.redirectTo({ url: route });
+    return;
+  }
+
+  Taro.showToast({
+    title: `${item.label}功能待接入`,
+    icon: "none"
+  });
+}