feat: toggle hidden directories in cd-browser with . key

tests/test_cli.py

@@ -4,9 +4,10 @@ import pytest
 
 from app.cli import run_cli
 from app.navigator import Navigator
+from app.ui import TerminalUI
 
 
-class StubUI:
+class StubUI(TerminalUI):
     def __init__(self, result: Path) -> None:
         self.result = result
         self.navigator: Navigator | None = None

tests/test_navigator.py

@@ -25,6 +25,31 @@ def test_navigator_initial_state_includes_parent_entry(tmp_path: Path) -> None:
     ]
 
 
+def test_toggle_hidden_directories(tmp_path: Path) -> None:
+    root = tmp_path / "root"
+    root.mkdir()
+    visible = root / "visible"
+    visible.mkdir()
+    hidden = root / ".hidden"
+    hidden.mkdir()
+
+    navigator = Navigator(root)
+
+    assert [entry.name for entry in navigator.visible_entries] == ["..", "visible"]
+
+    navigator.toggle_hidden()
+    assert navigator.show_hidden is True
+    assert [entry.name for entry in navigator.visible_entries] == [
+        "..",
+        ".hidden",
+        "visible",
+    ]
+
+    navigator.toggle_hidden()
+    assert navigator.show_hidden is False
+    assert [entry.name for entry in navigator.visible_entries] == ["..", "visible"]
+
+
 def test_expand_selected_directory_reveals_nested_entries(tmp_path: Path) -> None:
     current = tmp_path / "workspace"
     current.mkdir()