style(admin): remove redundant introductions and collapse contextual guidance

src/modules/iam/pages/InternalUsersView.vue

@@ -431,7 +431,7 @@ onMounted(loadInitialData)
 
     <AppDialog v-model="editorOpen" :title="editorLabel" width="min(650px, calc(100vw - 28px))" class="internal-user-editor-dialog admin-density-dialog iam-density" destroy-on-close :confirm-loading="saving" :confirm-text="editingUser ? '保存修改' : '确认添加'" @confirm="saveUser">
       <el-form class="density-form" ref="formRef" :model="form" :rules="formRules" label-position="top">
-        <FormSection class="density-form-section" title="用户资料" description="维护登录身份、联系方式与平台角色。">
+        <FormSection class="density-form-section" title="用户资料">
           <div class="form-grid two-cols">
           <el-form-item label="用户名" prop="username" required>
             <el-input v-model="form.username" :disabled="Boolean(editingUser)" placeholder="登录用户名" maxlength="64" />

src/modules/iam/pages/RolesView.vue

@@ -264,7 +264,7 @@ onMounted(loadRoles)
     <AppDialog v-model="editorOpen" :title="form.id ? '配置角色' : '新增角色'" width="min(860px, calc(100vw - 28px))" class="role-editor-dialog admin-density-dialog iam-density" :confirm-loading="saving" confirm-text="保存角色" :show-confirm="form.id ? canEdit || canGrant : canCreate" destroy-on-close @opened="initializePermissionSelection" @confirm="saveRole">
       <el-form ref="formRef" :model="form" :rules="formRules" label-position="top" class="role-editor-form density-form">
         <div class="role-editor-layout">
-          <FormSection title="基本信息" description="维护角色名称、编码和职责说明。" class="role-editor-basic density-form-section">
+          <FormSection title="基本信息" class="role-editor-basic density-form-section">
             <el-form-item label="角色名称" prop="name" required><el-input v-model="form.name" :disabled="Boolean(form.id) && !canEdit" placeholder="如：订单运营专员" maxlength="64" /></el-form-item>
             <el-form-item label="角色编码" prop="code" required><el-input v-model="form.code" :disabled="Boolean(form.id)" placeholder="如：ORDER_OPERATOR" maxlength="64" /></el-form-item>
             <el-form-item label="角色说明"><el-input v-model="form.description" :disabled="Boolean(form.id) && !canEdit" type="textarea" :rows="3" placeholder="说明该角色的工作范围" maxlength="200" show-word-limit /></el-form-item>