feat!: replace rsyncwrapper with local rsync module

Add src/rsync.js as a drop-in replacement for rsyncwrapper, using
child_process.spawn directly. Only implements the options this project
uses. Single line change in rsyncCli.js to swap the import.

BREAKING CHANGE: rsyncwrapper dependency removed, rsync command is now
constructed and executed via a local module using child_process.spawn.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/rsync.js

@@ -0,0 +1,54 @@
+const { spawn } = require('child_process');
+
+const escapeSpaces = (str) => (typeof str === 'string' ? str.replace(/\b\s/g, '\\ ') : str);
+
+const buildRsyncCommand = ({ src, dest, excludeFirst, port, privateKey, args, sshCmdArgs }) => {
+  const cmdParts = [];
+
+  const sources = Array.isArray(src) ? src : [src];
+  cmdParts.push(...sources.map(escapeSpaces));
+  cmdParts.push(escapeSpaces(dest));
+
+  let sshCmd = `ssh -p ${port || 22} -i ${privateKey}`;
+  if (sshCmdArgs && sshCmdArgs.length > 0) {
+    sshCmd += ` ${sshCmdArgs.join(' ')}`;
+  }
+  cmdParts.push('--rsh', `"${sshCmd}"`);
+
+  cmdParts.push('--recursive');
+
+  if (Array.isArray(excludeFirst)) {
+    excludeFirst.forEach((pattern) => {
+      if (pattern) cmdParts.push(`--exclude=${escapeSpaces(pattern)}`);
+    });
+  }
+
+  if (Array.isArray(args)) {
+    cmdParts.push(...args);
+  }
+
+  return `rsync ${[...new Set(cmdParts)].join(' ')}`;
+};
+
+module.exports = (options, callback) => {
+  const cmd = buildRsyncCommand(options);
+  const noop = () => {};
+  const onStdout = options.onStdout || noop;
+  const onStderr = options.onStderr || noop;
+
+  let stdout = '';
+  let stderr = '';
+  const proc = spawn('/bin/sh', ['-c', cmd]);
+
+  proc.stdout.on('data', (data) => { onStdout(data); stdout += data; });
+  proc.stderr.on('data', (data) => { onStderr(data); stderr += data; });
+
+  proc.on('exit', (code) => {
+    let error = null;
+    if (code !== 0) {
+      error = new Error(`rsync exited with code ${code}`);
+      error.code = code;
+    }
+    callback(error, stdout, stderr, cmd);
+  });
+};