Hoist shlex to module-level import in cli

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/hqt/cli.py

@@ -1,5 +1,6 @@
 import logging
 import os
+import shlex
 import subprocess
 import sys
 import traceback
@@ -185,8 +186,6 @@ def _palette_popup_command(window: str) -> str:
     concrete here (run-shell already expanded #{window_name} before `hqt palette`
     ran). The selected entry runs `hqt tool <choice> <window>`.
     """
-    import shlex
-
     entries = "\\n".join(PALETTE_ENTRIES) + "\\n"
     return (
         f"printf '{entries}' | "