fix(pi-ssh): harden remote execution and search

pi-ssh/test/remote-bash.test.ts

@@ -0,0 +1,43 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { createRemoteBashOps } from "../src/remote-bash.ts";
+import type { RemoteExecOptions, RemoteTransport } from "../src/ssh2-transport.ts";
+
+class CapturingTransport implements RemoteTransport {
+  calls: Array<{ command: string; cwd: string }> = [];
+  connect(): Promise<void> { return Promise.resolve(); }
+  dispose(): Promise<void> { return Promise.resolve(); }
+  exec(command: string, cwd: string, options: RemoteExecOptions): Promise<{ exitCode: number | null }> {
+    this.calls.push({ command, cwd });
+    options.onData(Buffer.from("ok\n"));
+    return Promise.resolve({ exitCode: 0 });
+  }
+  capture(): Promise<{ exitCode: number | null; output: Buffer }> { throw new Error("not used"); }
+  readFile(): Promise<Buffer> { throw new Error("not used"); }
+  ensureReadable(): Promise<void> { throw new Error("not used"); }
+  ensureReadableWritable(): Promise<void> { throw new Error("not used"); }
+  detectImageMimeType(): Promise<string | null> { throw new Error("not used"); }
+  mkdir(): Promise<void> { throw new Error("not used"); }
+  writeFile(): Promise<void> { throw new Error("not used"); }
+}
+
+test("ssh_bash always executes from the active remote cwd", async () => {
+  const connection = { remoteCwd: "/srv/project" };
+  const transport = new CapturingTransport();
+  const operations = createRemoteBashOps(connection, transport);
+
+  await operations.exec("pwd", "/Users/local/project", { onData() {} });
+  assert.deepEqual(transport.calls, [{ command: "pwd", cwd: "/srv/project" }]);
+
+  connection.remoteCwd = "/opt/next-project";
+  await operations.exec("npm test", "/another/local/path", { onData() {} });
+  assert.deepEqual(transport.calls[1], { command: "npm test", cwd: "/opt/next-project" });
+});
+
+test("ssh_bash rejects an invalid non-absolute remote cwd", () => {
+  const operations = createRemoteBashOps({ remoteCwd: "relative/path" }, new CapturingTransport());
+  assert.throws(
+    () => operations.exec("pwd", "/Users/local/project", { onData() {} }),
+    /requires an absolute remote cwd/,
+  );
+});