feat(ui/agents): add AgentList component

antd Table that renders cloud-agent definitions and links each row to
/agents/{agent_id}. Uses Tag for the model and dayjs.fromNow for the
last-activity column. Empty state is the antd Empty placeholder.

ui/litellm-dashboard/src/app/(dashboard)/agents/components/agent-list.tsx

@@ -0,0 +1,62 @@
+"use client";
+
+import Link from "next/link";
+import { Card, Table, Tag, Typography, Empty } from "antd";
+import type { ColumnsType } from "antd/es/table";
+import dayjs from "dayjs";
+import type { CloudAgent } from "@/types/cloud-agents";
+
+const { Text } = Typography;
+
+interface AgentListProps {
+  agents: CloudAgent[];
+  loading: boolean;
+}
+
+export default function AgentList({ agents, loading }: AgentListProps) {
+  const columns: ColumnsType<CloudAgent> = [
+    {
+      title: "Name",
+      dataIndex: "name",
+      key: "name",
+      render: (_value: unknown, record: CloudAgent) => (
+        <Link href={`/agents/${record.agent_id}`} data-testid={`agent-link-${record.agent_id}`}>
+          <Text strong>{record.name}</Text>
+        </Link>
+      ),
+    },
+    {
+      title: "Model",
+      dataIndex: "model",
+      key: "model",
+      render: (value: string) => <Tag color="blue">{value}</Tag>,
+    },
+    {
+      title: "Sessions",
+      dataIndex: "session_count",
+      key: "session_count",
+      width: 100,
+    },
+    {
+      title: "Last activity",
+      dataIndex: "last_activity_at",
+      key: "last_activity_at",
+      render: (value: string | null) => (value ? dayjs(value).fromNow?.() ?? dayjs(value).format("YYYY-MM-DD HH:mm") : "—"),
+    },
+  ];
+
+  return (
+    <Card>
+      <Table<CloudAgent>
+        rowKey="agent_id"
+        dataSource={agents}
+        columns={columns}
+        loading={loading}
+        locale={{
+          emptyText: <Empty description="No cloud agents yet — create your first one." />,
+        }}
+        data-testid="agents-table"
+      />
+    </Card>
+  );
+}