feat: Agent采集uptime, 后端持久化kernel/uptime/diskIO, 前端磁盘BPS+IOPS展示

- Agent: system.go 添加 readUptime(), SystemStat 携带 Uptime
- Backend: Server 模型新增 Kernel 字段, ReceiveReport 持久化 kernel+uptime
- Backend: /agent/latest 返回 kernel/uptime/port_info/disk_io_info/disk_total
- Frontend: 磁盘监控改为 BPS+IOPS (4张卡片), 系统信息修复内核/运行时长/监听端口/磁盘容量
- 图表单位从 MB/s 改为 KB/s, 添加 formatBPS 工具函数

frontend/src/components/server/TerminalDialog.tsx

@@ -5,12 +5,15 @@ import {
   DialogDescription,
   DialogTitle,
 } from '@/components/ui/dialog';
+import { Button } from '@/components/ui/button';
 import { Terminal as XTerm } from 'xterm';
 import { FitAddon } from 'xterm-addon-fit';
 import 'xterm/css/xterm.css';
-import { Maximize2, Minimize2, X } from 'lucide-react';
+import { Maximize2, Minimize2, X, Key, Shield } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import { useUserStore } from '@/store';
+import { credentialApi, serverCredentialApi } from '@/services/api';
+import { toast } from 'sonner';
 
 interface TerminalDialogProps {
   open: boolean;
@@ -18,6 +21,8 @@ interface TerminalDialogProps {
   serverId: number | null;
   serverName: string;
   serverIp: string;
+  /** 服务器是否有可用的认证凭据（密码或SSH密钥） */
+  hasAuth?: boolean;
 }
 
 /**
@@ -30,6 +35,7 @@ export function TerminalDialog({
   serverId,
   serverName,
   serverIp,
+  hasAuth = true,
 }: TerminalDialogProps) {
   const containerRef = useRef<HTMLDivElement>(null);
   const termRef = useRef<XTerm | null>(null);
@@ -38,9 +44,44 @@ export function TerminalDialog({
   const [connected, setConnected] = useState(false);
   const [fullscreen, setFullscreen] = useState(false);
 
-  // 连接终端
+  // 凭据选择状态（hasAuth=false 时显示） // Logan.Li
+  const [credentials, setCredentials] = useState<any[]>([]);
+  const [selectedCredId, setSelectedCredId] = useState<string>('');
+  const [assigning, setAssigning] = useState(false);
+  const [authReady, setAuthReady] = useState(hasAuth); // 认证就绪标志
+
+  // 加载凭据列表
   useEffect(() => {
-    if (!open || !serverId) return;
+    if (!open || hasAuth) return;
+    credentialApi.list().then((res: any) => setCredentials(res?.list || [])).catch(() => {});
+  }, [open, hasAuth]);
+
+  // 关联凭据
+  const handleAssignCredential = async () => {
+    if (!selectedCredId || !serverId) return;
+    try {
+      setAssigning(true);
+      await serverCredentialApi.assign(serverId, Number(selectedCredId));
+      toast.success('凭据已关联');
+      setAuthReady(true);
+    } catch (e: any) {
+      toast.error(e?.message || '关联失败');
+    } finally {
+      setAssigning(false);
+    }
+  };
+
+  // 重置状态
+  useEffect(() => {
+    if (!open) {
+      setAuthReady(hasAuth);
+      setSelectedCredId('');
+    }
+  }, [open, hasAuth]);
+
+  // 连接终端（authReady=true 时才执行）
+  useEffect(() => {
+    if (!open || !serverId || !authReady) return;
 
     // 创建终端
     const term = new XTerm({
@@ -115,7 +156,7 @@ export function TerminalDialog({
       wsRef.current = null;
       setConnected(false);
     };
-  }, [open, serverId]);
+  }, [open, serverId, authReady]);
 
   // 用 ResizeObserver 监听容器实际尺寸变化，自动 fit 终端
   // 这比 window resize 或 setTimeout 更可靠：
@@ -189,12 +230,47 @@ export function TerminalDialog({
             </button>
           </div>
         </div>
+        {/* 凭据选择器（无认证凭据时显示） */} 
+        {!authReady && (
+          <div className="p-6 flex flex-col items-center justify-center gap-4" style={{ height: '480px' }}>
+            <Shield className="h-12 w-12 text-amber-400" />
+            <div className="text-center">
+              <p className="text-[var(--dg-text-primary)] font-medium mb-1">服务器未配置认证凭据</p>
+              <p className="text-sm text-[var(--dg-text-muted)]">请选择一个凭据用于 SSH 连接</p>
+            </div>
+            {credentials.length === 0 ? (
+              <p className="text-xs text-[var(--dg-text-muted)]">暂无可用凭据，请先去「凭证配置」添加</p>
+            ) : (
+              <select
+                value={selectedCredId}
+                onChange={(e) => setSelectedCredId(e.target.value)}
+                className="w-64 px-3 py-2 bg-[var(--dg-bg-tertiary)] border border-[var(--dg-border)] rounded-md text-[var(--dg-text-primary)] text-sm"
+              >
+                <option value="">-- 选择凭据 --</option>
+                {credentials.map((c: any) => (
+                  <option key={c.id} value={String(c.id)}>
+                    {c.type === 'ssh_key' ? '🔑' : '🔒'} {c.name}
+                  </option>
+                ))}
+              </select>
+            )}
+            <Button
+              onClick={handleAssignCredential}
+              disabled={!selectedCredId || assigning}
+              className="bg-[var(--dg-blue)] hover:opacity-90 text-white"
+            >
+              {assigning ? '关联中...' : '确认连接'}
+            </Button>
+          </div>
+        )}
         {/* 终端容器 */}
-        <div
-          ref={containerRef}
-          className="bg-[#0a0e14]"
-          style={{ height: fullscreen ? 'calc(100vh - 49px)' : '480px' }}
-        />
+        {authReady && (
+          <div
+            ref={containerRef}
+            className="bg-[#0a0e14]"
+            style={{ height: fullscreen ? 'calc(100vh - 49px)' : '480px' }}
+          />
+        )}
       </DialogContent>
     </Dialog>
   );