优化首页的ui交互，解决打包生产环境下写入sessionStorage错误，优化权限路由的跳转问题

app/routes/_index.tsx

@@ -151,7 +151,7 @@ export default function Index() {
               tabIndex={0}
               aria-label="合同管理"
             >
-              <i className="ri-file-list-2-fill text-[3rem] text-[#269b6c]"></i>
+              <img src="/images/icon_hetong.png" alt="合同管理" className="w-12 h-12 mx-1" />
               <span className="module-name">合同管理</span>
             </div>
 
@@ -164,7 +164,7 @@ export default function Index() {
               tabIndex={0}
               aria-label="案卷智能评查"
             >
-              <i className="ri-folder-shared-fill text-[3rem] text-[#269b6c]"></i>
+              <img src="/images/icon_anjuan.png" alt="案卷智能评查" className="w-12 h-12" />
               <span className="module-name">案卷智能评查</span>
             </div>
 
@@ -177,7 +177,7 @@ export default function Index() {
               tabIndex={0}
               aria-label="智慧法务大模型"
             >
-              <i className="ri-robot-2-fill text-[3rem] text-[#269b6c]"></i>
+              <img src="/images/icon_assistant.png" alt="智慧法务大模型" className="w-12 h-12" />
               <span className="module-name">智慧法务大模型</span>
             </div>
           </div>