refactor(cli): vim mode is a config key only — drop the /vim slash command

Maintainer ruling: no new slash command for this. `display.vim_mode: true`
in config.yaml enables vi keybindings in the composer at startup; the
NORMAL/INSERT/REPLACE status-bar label stays. Removes the CommandDef, the
handler, its dispatch-table entry and slash-command docs; documents the key
under Display Settings.

tests/cli/test_slash_dispatch_table.py

@@ -18,7 +18,6 @@ OLD_CHAIN_COMMANDS = [
     "blueprint", "curator", "kanban", "skills", "learn", "init", "memory",
     "platforms", "status", "context", "egress", "statusbar", "diff", "battery",
     "timestamps", "verbose", "focus", "footer", "yolo", "approvals", "reasoning",
-    "vim",
     "fast", "compress", "usage", "subscription", "topup", "insights", "copy",
     "debug", "update", "version", "paste", "image", "reload", "reload-mcp",
     "reload-skills", "bundles", "browser", "plugins", "rollback", "snapshot",

tests/cli/test_vim_mode_command.py

@@ -1,8 +1,7 @@
-"""Tests for the /vim CLI command and display.vim_mode config handling."""
+"""display.vim_mode: config-only vi keybindings for the CLI composer."""
 
 import unittest
 from types import SimpleNamespace
-from unittest.mock import patch
 
 from prompt_toolkit.enums import EditingMode
 
@@ -13,48 +12,6 @@ def _import_cli():
     return cli_mod
 
 
-class TestHandleVimCommand(unittest.TestCase):
-    """/vim toggles vi editing mode, persists it, and applies it live."""
-
-    def _make_cli(self, vim_mode=False, app=None):
-        return SimpleNamespace(
-            _vim_mode=vim_mode,
-            _app=app,
-            _console_print=lambda *a, **k: None,
-        )
-
-    def test_toggle_persists_and_applies_to_running_app(self):
-        cli_mod = _import_cli()
-        app = SimpleNamespace(editing_mode=EditingMode.EMACS)
-        stub = self._make_cli(vim_mode=False, app=app)
-
-        with patch.object(cli_mod, "save_config_value") as mock_save:
-            cli_mod.HermesCLI._handle_vim_command(stub, "/vim")
-        self.assertTrue(stub._vim_mode)
-        self.assertEqual(app.editing_mode, EditingMode.VI)
-        mock_save.assert_called_once_with("display.vim_mode", True)
-
-        with patch.object(cli_mod, "save_config_value") as mock_save:
-            cli_mod.HermesCLI._handle_vim_command(stub, "/vim off")
-        self.assertFalse(stub._vim_mode)
-        self.assertEqual(app.editing_mode, EditingMode.EMACS)
-        mock_save.assert_called_once_with("display.vim_mode", False)
-
-    def test_status_and_invalid_args_change_nothing(self):
-        cli_mod = _import_cli()
-        printed = []
-        stub = self._make_cli(vim_mode=True)
-        stub._console_print = lambda msg: printed.append(str(msg))
-
-        with patch.object(cli_mod, "save_config_value") as mock_save:
-            cli_mod.HermesCLI._handle_vim_command(stub, "/vim status")
-            cli_mod.HermesCLI._handle_vim_command(stub, "/vim sideways")
-
-        mock_save.assert_not_called()
-        self.assertTrue(stub._vim_mode)
-        self.assertIn("Usage", " ".join(printed))
-
-
 class TestVimModeLabel(unittest.TestCase):
     """The status-bar label reflects the live vi input mode; off/no-app yields empty."""
 
@@ -76,5 +33,14 @@ class TestVimModeLabel(unittest.TestCase):
         self.assertEqual(cli_mod.HermesCLI._vim_mode_label(stub), "REPLACE")
 
 
+class TestNoSlashCommand(unittest.TestCase):
+    """vim_mode is a config key only: no /vim command is registered."""
+
+    def test_vim_not_in_command_registry(self):
+        from hermes_cli.commands import COMMAND_REGISTRY
+
+        self.assertNotIn("vim", {c.name for c in COMMAND_REGISTRY})
+
+
 if __name__ == "__main__":
     unittest.main()