fix(auth/templates): 修复模板中request.contextPath的空指针问题

- 在confirm.ftl和login.ftl模板中增加request对象判空逻辑
- 优化OAuth2授权和登录表单的action路径安全性

pigx-auth/src/main/resources/templates/ftl/confirm.ftl

@@ -18,7 +18,8 @@
 		</div>
 	</div>
 
-	<form id='confirmationForm' name='confirmationForm' action="${request.contextPath}/oauth2/authorize" method='post'>
+	<form id='confirmationForm' name='confirmationForm'
+		  action="<#if request??>${request.contextPath!}</#if>/oauth2/authorize" method='post'>
 		<input type="hidden" name="client_id" value="${clientId}">
 		<input type="hidden" name="state" value="${state}">
 

pigx-auth/src/main/resources/templates/ftl/login.ftl

@@ -12,7 +12,7 @@
         <p class="mt-2 text-sm text-gray-600 dark:text-gray-400">安全便捷的企业级认证服务</p>
     </div>
 
-    <form class="form-signin" action="${request.contextPath}/oauth2/form" method="post">
+    <form class="form-signin" action="<#if request??>${request.contextPath!}</#if>/oauth2/form" method="post">
         <input type="hidden" name="client_id" value="pig">
         <input type="hidden" name="grant_type" value="password">
         <div class="space-y-6">