test(cli): RED — graph build lacks the tier hint for namespaced ids (#244)

RED pin: graph_build_hints_attach_for_namespaced_ids_in_a_data_only_project
(graph_construct.rs e2e) — the op-script path reports OpError::
UnknownNodeType without consulting the tier-aware hint the blueprint
load path carries.

refs #244

crates/aura-cli/tests/graph_construct.rs

@@ -1214,3 +1214,58 @@ fn graph_build_gang_on_a_bound_member_reports_unknown_param() {
         "the bound member reads as an ordinary unknown param, not a gang-specific fault: {stderr}"
     );
 }
+
+/// Like `run_in`, but also pipes `stdin_doc` to the child — the combination
+/// `aura graph build` needs, since it reads its op-script from stdin AND must
+/// discover the project from the working directory. Neither `run` (stdin, no
+/// cwd) nor `run_in` (cwd, no stdin) covers both.
+fn run_in_stdin(
+    dir: &std::path::Path,
+    args: &[&str],
+    stdin_doc: &str,
+) -> (String, String, Option<i32>) {
+    let mut child = Command::new(BIN)
+        .args(args)
+        .current_dir(dir)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()
+        .expect("spawn aura");
+    child.stdin.take().unwrap().write_all(stdin_doc.as_bytes()).unwrap();
+    let out = child.wait_with_output().expect("wait aura");
+    (
+        String::from_utf8_lossy(&out.stdout).into_owned(),
+        String::from_utf8_lossy(&out.stderr).into_owned(),
+        out.status.code(),
+    )
+}
+
+/// Property (#244): the tier-aware unresolved-namespace hint fires on the
+/// op-script `aura graph build` path exactly as it does on the blueprint LOAD
+/// path (`project_load.rs::data_only_project_hints_attach_for_namespaced_ids`,
+/// which this mirrors). Inside a data-only project (a bare `Aura.toml`, no node
+/// crate attached), an op-script referencing a project-namespaced type
+/// (`nosuch::Node`) the vocabulary cannot resolve refuses non-zero AND the
+/// refusal carries the tier hint — "binds no node crate" + the `aura nodes new`
+/// attach verb — not the bare unknown-type error. Same consumer mistake, same
+/// diagnostic quality across both entry surfaces. (The refusal/non-zero exit
+/// already works today; the hint text is the absent behaviour.)
+#[test]
+fn graph_build_hints_attach_for_namespaced_ids_in_a_data_only_project() {
+    let dir = temp_cwd("graph-build-dataonly-hint");
+    std::fs::write(dir.join("Aura.toml"), "").expect("write bare Aura.toml");
+    // A single op is enough: `replay` fails fast at the unknown-type `add`.
+    let ops = r#"[{"op":"add","type":"nosuch::Node","name":"n"}]"#;
+    let (stdout, stderr, code) = run_in_stdin(&dir, &["graph", "build"], ops);
+    assert_ne!(code, Some(0), "an unresolvable namespaced type refuses: {stderr}");
+    assert!(stdout.is_empty(), "no blueprint emitted on a fault: {stdout}");
+    assert!(
+        stderr.contains("binds no node crate"),
+        "the data-only tier hint fires on the graph-build path: {stderr}"
+    );
+    assert!(
+        stderr.contains("aura nodes new"),
+        "the hint points at the attach verb: {stderr}"
+    );
+}