chore: v0.6.0 baseline — 主题美化前存档

已实现：HTTP/TCP/Banner 探测、90 天可用率、表格/卡片视图、
数据源过滤、UptimeRobot 双向兼容、服务端驱动的刷新节奏、
刷新接口滥用防护与信息泄露控制。

prober/node/lib/tcp-probe.js

@@ -0,0 +1,18 @@
+import net from 'node:net';
+
+export function probeTcp(monitor) {
+  const started = Date.now();
+  const timeoutMs = (monitor.timeout ?? 10) * 1000;
+  return new Promise((resolve) => {
+    const socket = net.createConnection({ host: monitor.host, port: monitor.port });
+    const finish = (status, detail) => {
+      socket.destroy();
+      resolve({ status, latency: Date.now() - started, code: null, detail });
+    };
+    socket.setTimeout(timeoutMs, () => finish('down', 'TCP 连接超时'));
+    socket.once('error', (err) =>
+      finish('down', err.code === 'ECONNREFUSED' ? '连接被拒绝（端口关闭）' : (err.code || err.message))
+    );
+    socket.once('connect', () => finish('up', '端口可连接'));
+  });
+}