feat(cph): add outline export command

crates/cph-check/tests/pipeline.rs

@@ -45,6 +45,23 @@ fn good_fixture_has_no_errors() {
     assert!(!report.has_errors());
 }
 
+#[test]
+fn outline_projects_parts_in_manifest_order() {
+    let (outline, report) = cph_check::outline(&mini_fixture());
+    assert_eq!(
+        report.error_count(),
+        0,
+        "outline should validate the fixture"
+    );
+    let outline = outline.expect("valid lesson should produce an outline");
+    assert_eq!(outline.title, "迷你示例课时");
+    assert_eq!(outline.children.len(), 3);
+    assert_eq!(outline.children[0].title, "开场对照导言");
+    assert_eq!(outline.children[1].kind, "section");
+    assert_eq!(outline.children[1].children[0].title, "量纲分析估计");
+    assert_eq!(outline.children[2].title, "自由落体");
+}
+
 #[test]
 fn unknown_kind_is_an_error() {
     // Build a throwaway lesson whose part declares kind "frob".