feat(socket-handler): implement direct socket passing for DNS and email services

- Add socket-handler mode eliminating internal port binding for improved performance
- Add `dnsDomain` config option for automatic DNS-over-HTTPS (DoH) setup
- Add `useSocketHandler` flag to email config for direct socket processing
- Update SmartProxy route generation to support socket-handler actions
- Integrate smartdns with manual HTTPS mode for DoH without port binding
- Add automatic route creation for DNS paths when dnsDomain is configured
- Update documentation with socket-handler configuration and benefits
- Improve resource efficiency by eliminating internal port forwarding

ts/plugins.ts

@@ -4,6 +4,7 @@ import * as fs from 'fs';
 import * as crypto from 'crypto';
 import * as http from 'http';
 import * as net from 'net';
+import * as os from 'os';
 import * as path from 'path';
 import * as tls from 'tls';
 import * as util from 'util';
@@ -14,6 +15,7 @@ export {
   crypto,
   http,
   net,
+  os,
   path,
   tls,
   util,