feat(cph): add outline export command

crates/cph-model/tests/fixtures/valid/manifest.toml

@@ -9,6 +9,7 @@ author = "范式教育教研组"
 [[children]]
 kind = "segment"
 path = "segments/intro"
+notes = "这一节补充一个直观例题"
 
 [[children]]
 kind = "lemma"

crates/cph-model/tests/load.rs

@@ -35,6 +35,17 @@ fn valid_two_part_lesson_loads_in_order_with_no_errors() {
     assert_eq!(lesson.parts.len(), 2);
     assert_eq!(lesson.parts[0].kind, "segment");
     assert_eq!(lesson.parts[0].path, PathBuf::from("segments/intro"));
+    assert_eq!(
+        lesson.parts[0].notes.as_deref(),
+        Some("这一节补充一个直观例题")
+    );
+    let outline = lesson.outline_document();
+    assert_eq!(outline.children[0].title, "intro");
+    assert_eq!(
+        outline.children[0].notes.as_deref(),
+        Some("这一节补充一个直观例题")
+    );
+    assert!(outline.children[0].children.is_empty());
     assert_eq!(lesson.parts[0].descriptor.kind, "segment");
     assert_eq!(lesson.parts[1].kind, "lemma");
     assert_eq!(lesson.parts[1].path, PathBuf::from("lemmas/young"));
@@ -45,8 +56,14 @@ fn valid_two_part_lesson_loads_in_order_with_no_errors() {
     assert_eq!(
         lesson.outline,
         vec![
-            OutlineEntry::Element { part_index: 0 },
-            OutlineEntry::Element { part_index: 1 },
+            OutlineEntry::Element {
+                part_index: 0,
+                depth: 0,
+            },
+            OutlineEntry::Element {
+                part_index: 1,
+                depth: 0,
+            },
         ]
     );
 
@@ -114,22 +131,36 @@ fn nested_sections_flatten_depth_first_with_correct_depths() {
     assert_eq!(
         lesson.outline,
         vec![
-            OutlineEntry::Element { part_index: 0 }, // segments/开场白
+            OutlineEntry::Element {
+                part_index: 0,
+                depth: 0,
+            }, // segments/开场白
             OutlineEntry::Section {
                 kind: "section".to_string(),
                 title: "导言簇".to_string(),
                 depth: 1,
+                notes: None,
                 path: PathBuf::from("导言簇"),
             },
-            OutlineEntry::Element { part_index: 1 }, // 导言簇/segments/子段一
+            OutlineEntry::Element {
+                part_index: 1,
+                depth: 1,
+            }, // 导言簇/segments/子段一
             OutlineEntry::Section {
                 kind: "section".to_string(),
                 title: "嵌套子节".to_string(),
                 depth: 2,
+                notes: None,
                 path: PathBuf::from("导言簇/嵌套子节"),
             },
-            OutlineEntry::Element { part_index: 2 }, // 导言簇/嵌套子节/lemmas/子引理
-            OutlineEntry::Element { part_index: 3 }, // 导言簇/segments/子段二
+            OutlineEntry::Element {
+                part_index: 2,
+                depth: 2,
+            }, // 导言簇/嵌套子节/lemmas/子引理
+            OutlineEntry::Element {
+                part_index: 3,
+                depth: 1,
+            }, // 导言簇/segments/子段二
         ]
     );