fix: dialog responsive sizing + clarify console password field

- All dialogs use width="90%" + max-width for responsive layout
- Clarify "控制台密码" → "火山控制台密码" with explanation hint
  (not AirGate login, but Volcengine console login for the sub-account)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/views/iam/IAMUserList.vue

@@ -93,7 +93,7 @@
     </el-card>
 
     <!-- Allocate Dialog -->
-    <el-dialog v-model="allocateVisible" title="额度变更" width="480px">
+    <el-dialog v-model="allocateVisible" title="额度变更" width="90%" style="max-width: 520px;">
       <div style="margin-bottom:16px; padding:12px; background:#f5f7fa; border-radius:8px;">
         <div>用户: <b>{{ allocateUser?.username }}</b></div>
         <div>当前额度: ¥{{ Number(allocateUser?.allocated_quota || 0).toLocaleString() }}</div>
@@ -133,7 +133,7 @@
     </el-dialog>
 
     <!-- Config Dialog -->
-    <el-dialog v-model="configVisible" title="监控配置" width="520px">
+    <el-dialog v-model="configVisible" title="监控配置" width="90%" style="max-width: 560px;">
       <el-form :model="configForm" label-width="140px">
         <el-form-item label="告警阶梯(%)">
           <div style="display:flex; gap:8px; flex-wrap:wrap; align-items:center;">
@@ -159,7 +159,7 @@
     </el-dialog>
 
     <!-- Projects Dialog -->
-    <el-dialog v-model="projectsDialogVisible" :title="`${projectsUser?.username} 关联项目`" width="680px">
+    <el-dialog v-model="projectsDialogVisible" :title="`${projectsUser?.username} 关联项目`" width="90%" style="max-width: 900px;">
       <div style="margin-bottom:12px; display:flex; gap:8px; align-items:center;">
         <el-select v-model="projectToAdd" placeholder="选择火山项目" filterable style="flex:1;"
                    :loading="volcProjectsLoading">
@@ -203,7 +203,7 @@
     </el-dialog>
 
     <!-- Quota History Dialog -->
-    <el-dialog v-model="historyVisible" :title="`${historyUser?.username} 额度划拨记录`" width="600px">
+    <el-dialog v-model="historyVisible" :title="`${historyUser?.username} 额度划拨记录`" width="90%" style="max-width: 800px;">
       <el-table :data="quotaHistory" stripe v-loading="historyLoading" empty-text="暂无划拨记录">
         <el-table-column prop="created_at" label="时间" width="180">
           <template #default="{ row }">{{ new Date(row.created_at).toLocaleString('zh-CN') }}</template>
@@ -224,7 +224,7 @@
     </el-dialog>
 
     <!-- Policies Dialog -->
-    <el-dialog v-model="policiesVisible" :title="`${policiesUser?.username} 权限策略`" width="650px">
+    <el-dialog v-model="policiesVisible" :title="`${policiesUser?.username} 权限策略`" width="90%" style="max-width: 850px;">
       <div style="margin-bottom:12px; display:flex; gap:8px;">
         <el-select v-model="policyToAttach" placeholder="选择要附加的策略" filterable style="flex:1;">
           <el-option-group label="常用策略">
@@ -250,7 +250,7 @@
     </el-dialog>
 
     <!-- Create User Dialog -->
-    <el-dialog v-model="showCreate" title="创建子账号" width="520px">
+    <el-dialog v-model="showCreate" title="创建子账号" width="90%" style="max-width: 580px;">
       <el-alert type="warning" :closable="false" style="margin-bottom:16px;"
                 description="创建后会在火山引擎生成 IAM 用户和 API 密钥。SecretKey 仅显示一次，请务必保存！" />
       <el-form :model="createForm" label-width="110px">
@@ -266,9 +266,12 @@
         <el-form-item label="手机号">
           <el-input v-model="createForm.phone" placeholder="选填，如 +8618000000000" />
         </el-form-item>
-        <el-form-item label="控制台密码">
+        <el-form-item label="火山控制台密码">
           <el-input v-model="createForm.password" type="password" show-password
-                    placeholder="选填，填了才开通控制台登录" />
+                    placeholder="选填" />
+          <div style="font-size:12px;color:#999;margin-top:4px;">
+            火山引擎网页后台的登录密码。不填则子账号无法登录火山网页后台，仅能通过 API Key 使用服务
+          </div>
         </el-form-item>
         <el-form-item label="关联项目">
           <el-select v-model="createForm.project_name" placeholder="选填" filterable clearable
@@ -285,7 +288,7 @@
     </el-dialog>
 
     <!-- Secret Key Display Dialog -->
-    <el-dialog v-model="showSecretKey" title="API 密钥已生成" width="520px" :close-on-click-modal="false">
+    <el-dialog v-model="showSecretKey" title="API 密钥已生成" width="90%" style="max-width: 580px;" :close-on-click-modal="false">
       <el-alert type="error" :closable="false" style="margin-bottom:16px;"
                 description="SecretAccessKey 仅此一次显示！关闭后无法再次获取，请立即复制保存。" />
       <el-descriptions :column="1" border>