feat(smartshell): Add passthrough option for exec methods and corresponding tests

test/test.passthrough.ts

@@ -0,0 +1,42 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as smartshell from '../ts/index.js';
+
+tap.test('should handle passthrough for interactive commands', async () => {
+  const testSmartshell = new smartshell.Smartshell({
+    executor: 'bash',
+    sourceFilePaths: [],
+  });
+  
+  // Test with a simple echo command that doesn't need input
+  const result = await testSmartshell.execPassthrough('echo "Testing passthrough"');
+  expect(result.exitCode).toEqual(0);
+  expect(result.stdout).toContain('Testing passthrough');
+});
+
+tap.test('should handle streaming passthrough', async () => {
+  const testSmartshell = new smartshell.Smartshell({
+    executor: 'bash',
+    sourceFilePaths: [],
+  });
+  
+  // Test streaming passthrough with a simple command
+  const streamingResult = await testSmartshell.execStreamingPassthrough('echo "Testing streaming passthrough"');
+  const finalResult = await streamingResult.finalPromise;
+  
+  expect(finalResult.exitCode).toEqual(0);
+  expect(finalResult.stdout).toContain('Testing streaming passthrough');
+});
+
+tap.test('should allow normal exec without passthrough', async () => {
+  const testSmartshell = new smartshell.Smartshell({
+    executor: 'bash',
+    sourceFilePaths: [],
+  });
+  
+  // Regular exec should still work as before
+  const result = await testSmartshell.exec('echo "Normal exec"');
+  expect(result.exitCode).toEqual(0);
+  expect(result.stdout).toContain('Normal exec');
+});
+
+export default tap.start();