feat(web): add local LiDAR websocket relay

integrations/iphone-lidar/web/relay.mjs

@@ -0,0 +1,61 @@
+import http from 'node:http';
+import { readFile } from 'node:fs/promises';
+import { extname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { WebSocketServer } from 'ws';
+
+const root = fileURLToPath(new URL('.', import.meta.url));
+const port = Number(process.env.PORT || 8787);
+const clients = new Set();
+
+const server = http.createServer(async (req, res) => {
+  const path = req.url === '/' ? '/index.html' : req.url?.split('?')[0] || '/index.html';
+  if (path.includes('..')) {
+    res.writeHead(400).end('bad path');
+    return;
+  }
+
+  try {
+    const data = await readFile(join(root, path));
+    const contentType = {
+      '.html': 'text/html; charset=utf-8',
+      '.js': 'text/javascript; charset=utf-8',
+      '.mjs': 'text/javascript; charset=utf-8',
+      '.css': 'text/css; charset=utf-8',
+    }[extname(path)] || 'application/octet-stream';
+    res.writeHead(200, { 'content-type': contentType, 'cache-control': 'no-store' });
+    res.end(data);
+  } catch {
+    res.writeHead(404).end('not found');
+  }
+});
+
+const wss = new WebSocketServer({ server, path: '/ws/lidar' });
+
+wss.on('connection', (socket) => {
+  clients.add(socket);
+  socket.on('close', () => clients.delete(socket));
+  socket.on('message', (data, isBinary) => {
+    if (isBinary || data.length > 2_000_000) return;
+
+    let packet;
+    try {
+      packet = JSON.parse(data.toString());
+    } catch {
+      return;
+    }
+
+    if (packet?.type !== 'ruview.lidar.depth.v1') return;
+
+    for (const peer of clients) {
+      if (peer !== socket && peer.readyState === peer.OPEN) {
+        peer.send(data);
+      }
+    }
+  });
+});
+
+server.listen(port, '0.0.0.0', () => {
+  console.log(`RuView iPhone LiDAR relay: http://0.0.0.0:${port}`);
+  console.log(`Native endpoint: ws://<host>:${port}/ws/lidar`);
+});