fix: Write error JSON envelope to stdout, not stderr

.github/pull_request_template.md

@@ -0,0 +1,49 @@
+## Summary
+
+* 
+
+## Test plan
+
+* `cargo fmt --all --check`
+* `cargo clippy --all-targets -- -D warnings`
+* `cargo test --all-targets`
+
+### Manual verification
+
+<!-- Describe how a reviewer can manually verify the change.
+     If the change requires building the CLI with a local path override, include
+     setup/teardown steps so they can test with and without the fix. -->
+
+**Setup:**
+
+```bash
+# In the cli repo, temporarily override the engine dependency:
+cd cli/rust
+# Edit Cargo.toml → cli-engine = { features = ["pkce-auth"], path = "../../cli-engine" }
+cargo build --release && cp target/release/gddy ~/.local/bin/gddy
+```
+
+**Test WITHOUT the fix (baseline):**
+
+```bash
+cd cli-engine && git checkout main
+cd cli/rust && cargo build --release && cp target/release/gddy ~/.local/bin/gddy
+# <command to reproduce the issue>
+# Expected: <describe broken behavior>
+```
+
+**Test WITH the fix:**
+
+```bash
+cd cli-engine && git checkout <this-branch>
+cd cli/rust && cargo build --release && cp target/release/gddy ~/.local/bin/gddy
+# <same command>
+# Expected: <describe fixed behavior>
+```
+
+**Cleanup:**
+
+```bash
+# Revert cli/rust/Cargo.toml back to:
+# cli-engine = { features = ["pkce-auth"], version = "<published-version>" }
+```

src/cli.rs

@@ -981,7 +981,7 @@ impl Cli {
         &self,
         args: I,
         stdout: &mut O,
-        stderr: &mut E,
+        _stderr: &mut E,
         shutdown: Shutdown,
     ) -> std::io::Result<ExitCode>
     where
@@ -999,11 +999,7 @@ impl Cli {
         {
             on_shutdown();
         }
-        if output.exit_code == 0 {
-            stdout.write_all(output.rendered.as_bytes())?;
-        } else {
-            stderr.write_all(output.rendered.as_bytes())?;
-        }
+        stdout.write_all(output.rendered.as_bytes())?;
         Ok(process_exit_code(output.exit_code))
     }
 

tests/foundation.rs

@@ -458,7 +458,7 @@ async fn cli_runtime_root_help_includes_find_commands_without_modules() {
 }
 
 #[tokio::test]
-async fn cli_execute_from_writes_success_to_stdout_and_errors_to_stderr() {
+async fn cli_execute_from_writes_all_output_to_stdout() {
     // execute_from publishes the config-derived User-Agent process-wide, so this
     // test shares the lock with the user-agent tests and restores the default
     // on exit (including panic) via the RAII guard, while the lock is held.
@@ -502,13 +502,13 @@ async fn cli_execute_from_writes_success_to_stdout_and_errors_to_stderr() {
         .await
         .expect("execute should write");
     assert_eq!(code, std::process::ExitCode::from(1));
-    assert!(stdout.is_empty());
-    let rendered = String::from_utf8(stderr).expect("utf8");
+    assert!(stderr.is_empty());
+    let rendered = String::from_utf8(stdout).expect("utf8");
     assert!(rendered.contains("missing"));
 }
 
 #[tokio::test]
-async fn cli_execute_from_shutdown_signal_writes_interrupt_to_stderr() {
+async fn cli_execute_from_shutdown_signal_writes_interrupt_to_stdout() {
     // execute_from_until_signal publishes the config-derived User-Agent
     // process-wide; share the lock and restore the default (panic-safe) like above.
     let _ua_guard = USER_AGENT_TEST_LOCK.lock().await;
@@ -540,9 +540,9 @@ async fn cli_execute_from_shutdown_signal_writes_interrupt_to_stderr() {
         .expect("execute should write interrupt output");
 
     assert_eq!(code, std::process::ExitCode::from(130));
-    assert!(stdout.is_empty());
+    assert!(stderr.is_empty());
     assert_eq!(
-        String::from_utf8(stderr).expect("stderr should be utf8"),
+        String::from_utf8(stdout).expect("stdout should be utf8"),
         "command interrupted\n"
     );
     assert_eq!(shutdown_count.load(Ordering::SeqCst), 1);