fix: remove premature stream cancellation from DisposableProcess

The previous approach cancelled streams in DisposableProcess cleanup, but this
was too early - bash.ts was still reading from them. Streams close naturally
when the process exits, so no explicit cancellation is needed.

The key fix is that bash.ts now awaits exitCode (which resolves after process
exits), then immediately cleans up readline interfaces and Node streams. This
prevents waiting for stream 'close' events that don't propagate over SSH.

Author: ammar-agent

src/runtime/LocalRuntime.ts

@@ -88,14 +88,8 @@ export class LocalRuntime implements Runtime {
     const stderr = Readable.toWeb(childProcess.stderr) as unknown as ReadableStream<Uint8Array>;
     const stdin = Writable.toWeb(childProcess.stdin) as unknown as WritableStream<Uint8Array>;
 
-    // Register cleanup for streams when process exits
-    // CRITICAL: These streams MUST be cancelled when process exits to prevent hangs
-    disposable.addCleanup(() => {
-      // eslint-disable-next-line @typescript-eslint/no-empty-function
-      stdout.cancel().catch(() => {});
-      // eslint-disable-next-line @typescript-eslint/no-empty-function
-      stderr.cancel().catch(() => {});
-    });
+    // No stream cleanup in DisposableProcess - streams close naturally when process exits
+    // bash.ts handles cleanup after waiting for exitCode
 
     // Track if we killed the process due to timeout or abort
     let timedOut = false;

src/runtime/SSHRuntime.ts

@@ -179,18 +179,8 @@ export class SSHRuntime implements Runtime {
     const stderr = Readable.toWeb(sshProcess.stderr) as unknown as ReadableStream<Uint8Array>;
     const stdin = Writable.toWeb(sshProcess.stdin) as unknown as WritableStream<Uint8Array>;
 
-    // Register cleanup for streams when process exits
-    // CRITICAL: These streams MUST be cancelled when process exits to prevent hangs
-    // from waiting for stream 'close' events that don't reliably propagate over SSH
-    disposable.addCleanup(() => {
-      // Cancel streams to immediately signal EOF
-      // Use catch to ignore errors if streams are already closed
-      // eslint-disable-next-line @typescript-eslint/no-empty-function
-      stdout.cancel().catch(() => {});
-      // eslint-disable-next-line @typescript-eslint/no-empty-function
-      stderr.cancel().catch(() => {});
-      // Don't abort stdin - it's already closed/aborted by bash tool
-    });
+    // No stream cleanup in DisposableProcess - streams close naturally when process exits
+    // bash.ts handles cleanup after waiting for exitCode
 
     // Track if we killed the process due to timeout or abort
     let timedOut = false;