feat(PortProxy): Add optional source IP preservation support in PortProxy

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartproxy',
-  version: '3.6.0',
+  version: '3.7.0',
   description: 'a proxy for handling high workloads of proxying'
 }

ts/smartproxy.portproxy.ts

@@ -17,6 +17,7 @@ export interface ProxySettings extends plugins.tls.TlsOptions {
   domains: DomainConfig[];
   sniEnabled?: boolean;
   defaultAllowedIPs?: string[];  // Optional default IP patterns if no matching domain found
+  preserveSourceIP?: boolean;    // Whether to preserve the client's source IP when proxying
 }
 
 export class PortProxy {
@@ -123,12 +124,18 @@ export class PortProxy {
       const domainConfig = serverName ? findMatchingDomain(serverName) : undefined;
       const targetHost = domainConfig?.targetIP || this.settings.toHost!;
       
-      // Create connection with IP binding to preserve original client IP
-      const to = plugins.net.createConnection({
+      // Create connection, optionally preserving the client's source IP
+      const connectionOptions: plugins.net.NetConnectOpts = {
         host: targetHost,
         port: this.settings.toPort,
-        localAddress: remoteIP.replace('::ffff:', ''), // Remove IPv6 mapping if present
-      });
+      };
+
+      // Only set localAddress if preserveSourceIP is enabled
+      if (this.settings.preserveSourceIP) {
+        connectionOptions.localAddress = remoteIP.replace('::ffff:', ''); // Remove IPv6 mapping if present
+      }
+
+      const to = plugins.net.createConnection(connectionOptions);
       console.log(`Connection established: ${remoteIP} -> ${targetHost}:${this.settings.toPort}${serverName ? ` (SNI: ${serverName})` : ''}`);
       from.setTimeout(120000);
       from.pipe(to);