fix: add KillMode=process so remote-control survives restarts

systemd's default KillMode=control-group kills all processes in the
cgroup on service restart, including the detached claude remote-control
process. KillMode=process only kills the main Node.js process, letting
detached children survive. restoreRemoteControl() already handles
reattaching on startup.

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

setup/service.test.ts

@@ -62,6 +62,7 @@ ExecStart=${nodePath} ${projectRoot}/dist/index.js
 WorkingDirectory=${projectRoot}
 Restart=always
 RestartSec=5
+KillMode=process
 Environment=HOME=${homeDir}
 Environment=PATH=/usr/local/bin:/usr/bin:/bin:${homeDir}/.local/bin
 StandardOutput=append:${projectRoot}/logs/nanoclaw.log
@@ -142,6 +143,16 @@ describe('systemd unit generation', () => {
     expect(unit).toContain('RestartSec=5');
   });
 
+  it('uses KillMode=process to preserve detached children', () => {
+    const unit = generateSystemdUnit(
+      '/usr/bin/node',
+      '/home/user/nanoclaw',
+      '/home/user',
+      false,
+    );
+    expect(unit).toContain('KillMode=process');
+  });
+
   it('sets correct ExecStart', () => {
     const unit = generateSystemdUnit(
       '/usr/bin/node',