feat: refresh course through workflow and goal loops

tests/test_chapter_readmes.py

@@ -0,0 +1,33 @@
+import py_compile
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+CHAPTERS = sorted(ROOT.glob("s[0-9][0-9]_*"))
+
+
+def test_every_chapter_uses_english_as_the_default_readme() -> None:
+    assert len(CHAPTERS) == 22
+
+    for chapter in CHAPTERS:
+        assert (chapter / "README.md").is_file()
+        assert (chapter / "README.zh.md").is_file()
+        assert (chapter / "README.ja.md").is_file()
+        assert not (chapter / "README.en.md").exists()
+
+
+def test_every_chapter_has_the_same_language_navigation() -> None:
+    expected = (
+        "[English](README.md) · [中文](README.zh.md) · "
+        "[日本語](README.ja.md)"
+    )
+
+    for chapter in CHAPTERS:
+        for filename in ("README.md", "README.zh.md", "README.ja.md"):
+            lines = (chapter / filename).read_text().splitlines()
+            assert lines[2] == expected
+
+
+def test_every_chapter_script_compiles_on_python_311() -> None:
+    for chapter in CHAPTERS:
+        _ = py_compile.compile(str(chapter / "code.py"), doraise=True)