refactor(notes): remove csv and jsonl output formats

Remove print_list_notes_csv, print_list_notes_jsonl, and csv_escape from
the notes list command. The --format flag's csv and jsonl variants added
complexity without meaningful adoption — robot mode already provides
structured JSON output. Notes now have two output paths: human (default)
and JSON (--robot).

Also removes the corresponding test coverage (csv_escape, csv_output).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/cli/commands/list_tests.rs

@@ -1269,60 +1269,6 @@ fn test_truncate_note_body() {
     assert!(result.ends_with("..."));
 }
 
-#[test]
-fn test_csv_escape_basic() {
-    assert_eq!(csv_escape("simple"), "simple");
-    assert_eq!(csv_escape("has,comma"), "\"has,comma\"");
-    assert_eq!(csv_escape("has\"quote"), "\"has\"\"quote\"");
-    assert_eq!(csv_escape("has\nnewline"), "\"has\nnewline\"");
-}
-
-#[test]
-fn test_csv_output_basic() {
-    let result = NoteListResult {
-        notes: vec![NoteListRow {
-            id: 1,
-            gitlab_id: 100,
-            author_username: "alice".to_string(),
-            body: Some("Hello, world".to_string()),
-            note_type: Some("DiffNote".to_string()),
-            is_system: false,
-            created_at: 1_000_000,
-            updated_at: 2_000_000,
-            position_new_path: Some("src/main.rs".to_string()),
-            position_new_line: Some(42),
-            position_old_path: None,
-            position_old_line: None,
-            resolvable: true,
-            resolved: false,
-            resolved_by: None,
-            noteable_type: Some("Issue".to_string()),
-            parent_iid: Some(7),
-            parent_title: Some("Test issue".to_string()),
-            project_path: "group/project".to_string(),
-        }],
-        total_count: 1,
-    };
-
-    // Verify csv_escape handles the comma in body correctly
-    let body = result.notes[0].body.as_deref().unwrap();
-    let escaped = csv_escape(body);
-    assert_eq!(escaped, "\"Hello, world\"");
-
-    // Verify the formatting helpers
-    assert_eq!(
-        format_note_type(result.notes[0].note_type.as_deref()),
-        "Diff"
-    );
-    assert_eq!(
-        format_note_parent(
-            result.notes[0].noteable_type.as_deref(),
-            result.notes[0].parent_iid,
-        ),
-        "Issue #7"
-    );
-}
-
 #[test]
 fn test_jsonl_output_one_per_line() {
     let result = NoteListResult {