feat(core): add SSH data access proxy CLI and core managers

ts/classes.portproxy.ts

@@ -0,0 +1,26 @@
+import { SshClient } from './classes.sshclient.js';
+import type { IProxyRequest } from './types.js';
+
+export class PortProxy {
+  constructor(private sshClient = new SshClient()) {}
+
+  public buildArgs(request: IProxyRequest): string[] {
+    this.validateLocalForward(request.localForward);
+    return this.sshClient.buildSshArgs(request.host, {
+      localForwards: [request.localForward],
+      extraArgs: ['-N'],
+      exitOnForwardFailure: true,
+    });
+  }
+
+  public async start(request: IProxyRequest): Promise<number> {
+    return this.sshClient.spawnInteractive('ssh', this.buildArgs(request));
+  }
+
+  private validateLocalForward(localForward: string): void {
+    const parts = localForward.split(':');
+    if (parts.length < 3) {
+      throw new Error('Local forward must look like <localPort>:<remoteHost>:<remotePort>');
+    }
+  }
+}