fix(desktop): session persistence — refresh/login/context/empty-content 4-bug fix

1. App.tsx: add restoreSession() call on startup to prevent redirect
   to login page after refresh (isRestoring guard + BootstrapScreen)
2. CloneManager: call syncAgents() after loadClones() to restore
   currentAgent and conversation history on app load
3. zclaw-memory: add get_or_create_session() so frontend session UUID
   is persisted directly — kernel no longer creates mismatched IDs
4. openai.rs: assistant message content must be non-empty for
   Kimi/Qwen APIs — replace empty content with meaningful placeholders

Also includes admin-v2 ModelServices unified page (merge providers +
models + API keys into expandable row layout)

admin-v2/src/pages/Usage.tsx

@@ -4,20 +4,24 @@
 
 import { useState } from 'react'
 import { useQuery } from '@tanstack/react-query'
-import { Card, Row, Col, Select, Spin, Alert, Statistic, Typography } from 'antd'
-import { ColumnWidthOutlined, ThunderboltOutlined } from '@ant-design/icons'
+import { Card, Col, Row, Select, Statistic } from 'antd'
+import { ThunderboltOutlined, ColumnWidthOutlined } from '@ant-design/icons'
 import type { ProColumns } from '@ant-design/pro-components'
 import { ProTable } from '@ant-design/pro-components'
-import { usageService } from '@/services/usage'
 import { telemetryService } from '@/services/telemetry'
+import { PageHeader } from '@/components/PageHeader'
+import { ErrorState } from '@/components/ErrorState'
 import type { DailyUsageStat, ModelUsageStat } from '@/types'
 
-const { Title } = Typography
-
 export default function Usage() {
   const [days, setDays] = useState(30)
 
-  const { data: dailyData, isLoading: dailyLoading, error: dailyError } = useQuery({
+  const {
+    data: dailyData,
+    isLoading: dailyLoading,
+    error: dailyError,
+    refetch,
+  } = useQuery({
     queryKey: ['usage-daily', days],
     queryFn: ({ signal }) => telemetryService.dailyStats({ days }, signal),
   })
@@ -28,7 +32,12 @@ export default function Usage() {
   })
 
   if (dailyError) {
-    return <Alert type="error" message="加载用量数据失败" description={(dailyError as Error).message} showIcon />
+    return (
+      <>
+        <PageHeader title="用量统计" description="查看模型使用情况和 Token 消耗" />
+        <ErrorState message={(dailyError as Error).message} onRetry={() => refetch()} />
+      </>
+    )
   }
 
   const totalRequests = dailyData?.reduce((s, d) => s + d.request_count, 0) ?? 0
@@ -36,22 +45,52 @@ export default function Usage() {
 
   const dailyColumns: ProColumns<DailyUsageStat>[] = [
     { title: '日期', dataIndex: 'day', width: 120 },
-    { title: '请求数', dataIndex: 'request_count', width: 100, render: (_, r) => r.request_count.toLocaleString() },
-    { title: '输入 Token', dataIndex: 'input_tokens', width: 120, render: (_, r) => r.input_tokens.toLocaleString() },
-    { title: '输出 Token', dataIndex: 'output_tokens', width: 120, render: (_, r) => r.output_tokens.toLocaleString() },
+    {
+      title: '请求数',
+      dataIndex: 'request_count',
+      width: 100,
+      render: (_, r) => r.request_count.toLocaleString(),
+    },
+    {
+      title: '输入 Token',
+      dataIndex: 'input_tokens',
+      width: 120,
+      render: (_, r) => r.input_tokens.toLocaleString(),
+    },
+    {
+      title: '输出 Token',
+      dataIndex: 'output_tokens',
+      width: 120,
+      render: (_, r) => r.output_tokens.toLocaleString(),
+    },
     { title: '设备数', dataIndex: 'unique_devices', width: 80 },
   ]
 
   const modelColumns: ProColumns<ModelUsageStat>[] = [
     { title: '模型', dataIndex: 'model_id', width: 200 },
-    { title: '请求数', dataIndex: 'request_count', width: 100, render: (_, r) => r.request_count.toLocaleString() },
-    { title: '输入 Token', dataIndex: 'input_tokens', width: 120, render: (_, r) => r.input_tokens.toLocaleString() },
-    { title: '输出 Token', dataIndex: 'output_tokens', width: 120, render: (_, r) => r.output_tokens.toLocaleString() },
+    {
+      title: '请求数',
+      dataIndex: 'request_count',
+      width: 100,
+      render: (_, r) => r.request_count.toLocaleString(),
+    },
+    {
+      title: '输入 Token',
+      dataIndex: 'input_tokens',
+      width: 120,
+      render: (_, r) => r.input_tokens.toLocaleString(),
+    },
+    {
+      title: '输出 Token',
+      dataIndex: 'output_tokens',
+      width: 120,
+      render: (_, r) => r.output_tokens.toLocaleString(),
+    },
     {
       title: '平均延迟',
       dataIndex: 'avg_latency_ms',
       width: 100,
-      render: (_, r) => r.avg_latency_ms ? `${Math.round(r.avg_latency_ms)}ms` : '-',
+      render: (_, r) => (r.avg_latency_ms ? `${Math.round(r.avg_latency_ms)}ms` : '-'),
     },
     {
       title: '成功率',
@@ -63,34 +102,66 @@ export default function Usage() {
 
   return (
     <div>
-      <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: 24 }}>
-        <Title level={4} style={{ margin: 0 }}>用量统计</Title>
-        <Select
-          value={days}
-          onChange={setDays}
-          options={[
-            { value: 7, label: '最近 7 天' },
-            { value: 30, label: '最近 30 天' },
-            { value: 90, label: '最近 90 天' },
-          ]}
-          style={{ width: 140 }}
-        />
-      </div>
+      <PageHeader
+        title="用量统计"
+        description="查看模型使用情况和 Token 消耗"
+        actions={
+          <Select
+            value={days}
+            onChange={setDays}
+            options={[
+              { value: 7, label: '最近 7 天' },
+              { value: 30, label: '最近 30 天' },
+              { value: 90, label: '最近 90 天' },
+            ]}
+            className="w-36"
+          />
+        }
+      />
 
-      <Row gutter={[16, 16]} style={{ marginBottom: 24 }}>
-        <Col span={12}>
-          <Card>
-            <Statistic title="总请求数" value={totalRequests} prefix={<ThunderboltOutlined />} />
+      {/* Summary Cards */}
+      <Row gutter={[16, 16]} className="mb-6">
+        <Col xs={24} sm={12}>
+          <Card className="hover:shadow-md transition-shadow duration-200">
+            <Statistic
+              title={
+                <span className="text-neutral-500 dark:text-neutral-400 text-xs font-medium uppercase tracking-wide">
+                  总请求数
+                </span>
+              }
+              value={totalRequests}
+              prefix={<ThunderboltOutlined style={{ color: '#863bff' }} />}
+              valueStyle={{ fontWeight: 600, color: '#863bff' }}
+            />
           </Card>
         </Col>
-        <Col span={12}>
-          <Card>
-            <Statistic title="总 Token 数" value={totalTokens} prefix={<ColumnWidthOutlined />} />
+        <Col xs={24} sm={12}>
+          <Card className="hover:shadow-md transition-shadow duration-200">
+            <Statistic
+              title={
+                <span className="text-neutral-500 dark:text-neutral-400 text-xs font-medium uppercase tracking-wide">
+                  总 Token 数
+                </span>
+              }
+              value={totalTokens}
+              prefix={<ColumnWidthOutlined style={{ color: '#47bfff' }} />}
+              valueStyle={{ fontWeight: 600, color: '#47bfff' }}
+            />
           </Card>
         </Col>
       </Row>
 
-      <Card title="每日统计" style={{ marginBottom: 24 }} size="small">
+      {/* Daily Stats */}
+      <Card
+        title={
+          <span className="text-sm font-semibold text-neutral-700 dark:text-neutral-300">
+            每日统计
+          </span>
+        }
+        className="mb-6"
+        size="small"
+        styles={{ body: { padding: 0 } }}
+      >
         <ProTable<DailyUsageStat>
           columns={dailyColumns}
           dataSource={dailyData ?? []}
@@ -103,7 +174,16 @@ export default function Usage() {
         />
       </Card>
 
-      <Card title="按模型统计" size="small">
+      {/* Model Stats */}
+      <Card
+        title={
+          <span className="text-sm font-semibold text-neutral-700 dark:text-neutral-300">
+            按模型统计
+          </span>
+        }
+        size="small"
+        styles={{ body: { padding: 0 } }}
+      >
         <ProTable<ModelUsageStat>
           columns={modelColumns}
           dataSource={modelData ?? []}