feat: 自动备份与保留策略、健康持续化与状态页、指标历史与趋势图，并修隧道判定误报与仪表盘布局（v1.2.11）

- 自动备份：每日一份（按最新备份是否在 24h 内判定，重启不重复）、保留份数可配、列表/下载/恢复/删除，恢复前先校验归档；顺手修 writeArchive 逐个检查 tar/gzip/文件 Close()（审查报告 §二）

- 健康持续化：只存状态变更（up/down/unknown）并推导可用率与不可用区间；公开状态页默认关闭、访问码存 SHA-256、按 IP 限流、只暴露域名与可用率

- 隧道判定修复：RouteHealthCandidate 新增 tunnel_known，frps 管理接口不可用时不再把「判不出来」当成「不通」（此前会误报「隧道连续不通」）；汇总与徽标同样区分「无法判定」

- 指标历史：metrics_samples 纵向点表（本机 CPU/内存/磁盘 + 每规则上下行，30 天保留、查询按桶平均、不做降采样表）；仪表盘趋势卡支持 1h/24h/7d

- 仪表盘布局：运行状态并入顶部统计区（运行时长补进「服务」卡）；性能并入系统资源那一行，整行 4 列

- 测试：backup/metrics/frp/api/app 新增用例；gofmt、go build/vet/test、vue-tsc、vite build 全绿

- agent 无改动，AgentVersion 保持 0.12.2

web/src/api/client.ts

@@ -349,6 +349,18 @@ export const api = {
     request<import('./types').FrpAgentRouteHealth[]>(`/api/frpmulti/servers/${serverId}/agent/routes/health`),
   getFrpRouteHealthSummary: () =>
     request<import('./types').FrpRouteHealthSummary>('/api/frpmulti/routes/summary'),
+  getFrpRouteUptime: (hours = 24) =>
+    request<{ hours: number; items: import('./types').FrpRouteUptime[] }>(`/api/frpmulti/routes/uptime?hours=${hours}`),
+
+  // 指标历史：窗口内的序列已按桶取平均，拿到就能直接画
+  getMetricsHistory: (hours = 24, buckets = 48) =>
+    request<import('./types').MetricsHistory>(`/api/metrics/history?hours=${hours}&buckets=${buckets}`),
+
+  // 匿名状态页：未开启或访问码不对时后端回 404
+  getStatusPage: (code?: string) =>
+    request<import('./types').StatusPagePayload>(
+      `/api/status-page${code ? `?code=${encodeURIComponent(code)}` : ''}`,
+    ),
   removeFrpAgentRoute: (serverId: number, proxyId: number) => request<{ ok: boolean }>(`/api/frpmulti/servers/${serverId}/agent/routes/${proxyId}`, { method: 'DELETE' }),
   pushFrpConfigToAgent: (id: number) => request<{ ok: boolean }>(`/api/frpmulti/servers/${id}/agent/frps-config`, { method: 'POST' }),
   frpsServerAction: (id: number, action: 'start' | 'stop' | 'restart') =>
@@ -399,6 +411,28 @@ export const api = {
     URL.revokeObjectURL(url)
   },
 
+  listBackupArchives: () =>
+    request<{ archives: import('./types').BackupArchive[]; keep: number }>('/api/backup/archives'),
+  createBackupArchive: () =>
+    request<{ name: string; removed: number }>('/api/backup/archives', { method: 'POST' }),
+  restoreBackupArchive: (name: string) =>
+    request<{ message: string }>(`/api/backup/archives/${encodeURIComponent(name)}/restore`, { method: 'POST' }),
+  deleteBackupArchive: (name: string) =>
+    request<{ ok: boolean }>(`/api/backup/archives/${encodeURIComponent(name)}`, { method: 'DELETE' }),
+  async downloadBackupArchive(name: string) {
+    const response = await fetch(`/api/backup/archives/${encodeURIComponent(name)}`, { credentials: 'include' })
+    if (!response.ok) {
+      throw new Error('下载备份失败')
+    }
+    const blob = await response.blob()
+    const url = URL.createObjectURL(blob)
+    const link = document.createElement('a')
+    link.href = url
+    link.download = name
+    link.click()
+    URL.revokeObjectURL(url)
+  },
+
   async restoreBackup(file: File) {
     const form = new FormData()
     form.append('file', file)