完善机构终端页面布局与登录页细节调整

frontend/components/dashboard/HeaderBar.tsx

@@ -10,6 +10,7 @@ import {
   RotateCw,
   BookOpen,
   MoreHorizontal,
+  CloudSun,
 } from "lucide-react";
 import { useEffect, useState } from "react";
 import { useDashboardStore, useProAccess } from "@/hooks/useDashboardStore";
@@ -95,8 +96,8 @@ export function HeaderBar({
   return (
     <header className="header">
       <div className="brand">
-        <span className="brand-mark" aria-hidden="true">
-          <Image src="/favicon-32x32.png" alt="" width={24} height={24} priority />
+        <span className="brand-mark bg-blue-600 !border-transparent flex items-center justify-center text-white" aria-hidden="true">
+          <CloudSun size={18} />
         </span>
         <h1>PolyWeather</h1>
         <span className="subtitle">{t("header.subtitle")}</span>