feat(pi-ssh): support SSH agent authentication

pi-ssh/test/ssh2-transport.test.ts

@@ -1,7 +1,7 @@
 import assert from "node:assert/strict";
 import { EventEmitter } from "node:events";
 import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
-import { tmpdir } from "node:os";
+import { homedir, tmpdir } from "node:os";
 import { join } from "node:path";
 import test from "node:test";
 import type { Client, ClientChannel, ConnectConfig, SFTPWrapper } from "ssh2";
@@ -235,6 +235,18 @@ test("loads private-key authentication and forwards the passphrase", async () =>
   }
 });
 
+test("forwards SSH agent authentication through ssh2", async () => {
+  const host: SshHostConfig = {
+    ...passwordHost(),
+    auth: { type: "agent", socketPath: "~/.1password/agent.sock" },
+  };
+  const { fake, transport } = await connectedTransport(undefined, host);
+  assert.equal(fake.connectConfig?.agent, join(homedir(), ".1password", "agent.sock"));
+  assert.equal(fake.connectConfig?.password, undefined);
+  assert.equal(fake.connectConfig?.privateKey, undefined);
+  await transport.dispose();
+});
+
 test("reads files, checks access modes, detects images, and reuses SFTP", async () => {
   const sftp = new FakeSftp();
   sftp.files.set("/srv/app/a.txt", Buffer.from("hello"));