Add shortcut help popup

tests/test_key_help.py

@@ -0,0 +1,55 @@
+from __future__ import annotations
+
+import argparse
+import curses
+import unittest
+from unittest.mock import Mock, patch
+
+from herdr_hub.cli import build_parser, command_keys
+from herdr_hub.key_help import KEY_SECTIONS, KeyHelpPopup
+
+
+class KeyHelpTests(unittest.TestCase):
+    def test_reference_contains_primary_hub_mappings(self) -> None:
+        mappings = {
+            mapping.keys: mapping.action
+            for _, section in KEY_SECTIONS
+            for mapping in section
+        }
+        for keys in (
+            "Ctrl+A ?",
+            "Ctrl+A g",
+            "Ctrl+A h",
+            "Ctrl+A r",
+            "Ctrl+A R",
+            "Ctrl+A q",
+            "Ctrl+A d",
+        ):
+            self.assertIn(keys, mappings)
+
+    def test_narrow_layout_stacks_keys_and_actions(self) -> None:
+        wide = [value for value, _ in KeyHelpPopup.lines(70)]
+        narrow = [value for value, _ in KeyHelpPopup.lines(36)]
+        self.assertGreater(len(narrow), len(wide))
+        self.assertIn("  Ctrl+A ?", narrow)
+        self.assertIn("    打开快捷键帮助", narrow)
+
+    def test_escape_closes_popup(self) -> None:
+        screen = Mock()
+        screen.getmaxyx.return_value = (24, 80)
+        screen.get_wch.return_value = "\x1b"
+        with patch("curses.set_escdelay"), patch("curses.curs_set"), patch(
+            "curses.use_default_colors"
+        ), patch("curses.mousemask"):
+            self.assertEqual(KeyHelpPopup().run(screen), 0)
+
+    def test_cli_entry_uses_curses_wrapper(self) -> None:
+        arguments = build_parser().parse_args(["keys"])
+        self.assertEqual(arguments.command, "keys")
+        with patch("herdr_hub.cli.curses.wrapper", return_value=0) as wrapper:
+            self.assertEqual(command_keys(argparse.Namespace()), 0)
+        wrapper.assert_called_once()
+
+
+if __name__ == "__main__":
+    unittest.main()