fix: support bounded recursive glob across lessons

tests/test_agent_loop_boundaries.py

@@ -30,6 +30,8 @@ LESSONS = tuple(
     )
 )
 INTEGRATED_LESSON = ROOT / "s15_integrated_harness" / "code.py"
+GOAL_LESSON = ROOT / "s17_goal_loop" / "code.py"
+GLOB_LESSONS = (*LESSONS[1:], INTEGRATED_LESSON, GOAL_LESSON)
 
 
 class FakeMessagesApi:
@@ -137,6 +139,42 @@ def bash_tool_call():
     )
 
 
+def run_glob_tool(lesson, workdir: Path, pattern: str) -> str:
+    if hasattr(lesson, "run_glob"):
+        return lesson.run_glob(pattern)
+    session = object.__new__(lesson.AgentSession)
+    session.workdir = workdir.resolve()
+    return session._run_tool("glob", {"pattern": pattern})
+
+
+@pytest.mark.parametrize("lesson_path", GLOB_LESSONS,
+                         ids=lambda path: path.parent.name)
+def test_glob_double_star_matches_files_at_any_depth(
+        tmp_path: Path, lesson_path: Path):
+    (tmp_path / "root.py").write_text("")
+    (tmp_path / "one" / "two").mkdir(parents=True)
+    (tmp_path / "one" / "one.py").write_text("")
+    (tmp_path / "one" / "two" / "deep.py").write_text("")
+    lesson = load_lesson(tmp_path, lesson_path)
+
+    matches = set(run_glob_tool(lesson, tmp_path, "**/*.py").splitlines())
+
+    assert matches == {"root.py", "one/one.py", "one/two/deep.py"}
+
+
+@pytest.mark.parametrize("lesson_path", GLOB_LESSONS,
+                         ids=lambda path: path.parent.name)
+def test_glob_caps_large_result_sets(tmp_path: Path, lesson_path: Path):
+    for index in range(205):
+        (tmp_path / f"file-{index:03}.txt").write_text("")
+    lesson = load_lesson(tmp_path, lesson_path)
+
+    lines = run_glob_tool(lesson, tmp_path, "*.txt").splitlines()
+
+    assert len(lines) == 201
+    assert lines[-1] == "... (more matches omitted; narrow the pattern)"
+
+
 @pytest.mark.parametrize("lesson_path", LESSONS, ids=lambda path: path.parent.name)
 @pytest.mark.parametrize("content", ([], None), ids=("empty-content", "empty-text"))
 def test_parent_loop_does_not_append_an_empty_tool_result_turn(