- ProxyManager: all ops (start/stop/reload, config push) work over SSH
when proxy_mode=remote; sysctl/reload/writeHostConfig/deleteHost all
route to remoteExec/remotePush helpers
- proxy.php: add GET/POST /api/proxy/settings and POST /api/proxy/test-remote
- admin.js: Settings modal with mode selector + remote fields + Test Connection;
page header always shows Settings button; status card shows mode + remote host;
'not installed' state directs to Configure Remote Proxy VM
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>