fix: expand shell variables in bash argPath for permission check (#740), allow leader keybinds when prompt focused (#674)

[MrRealORG]

Summary

Two targeted safety fixes in 2 files:

Fix #740 — Bash tool skips external directory permission for shell-variable paths

The argPath() function in bash.ts only called expand() (which resolves $HOME, $PWD etc.) for PowerShell. On bash, it only called home(unquote(arg)) which handles ~ but not $HOME.

Since the unexpanded text still contained $, dynamic() returned true, causing the entire external directory permission check to be skipped. This meant commands like rm -rf $HOME/project never triggered the directory permission prompt.

Fix: Call expand() for all shells, not just PowerShell. The function already handles both PowerShell ($env:X, ${env:X}) and bash ($HOME, $PWD) patterns.

Fix #674 — Leader-prefixed keybinds blocked when prompt is focused

In dialog-command.tsx, the keyboard handler skips non-input keybinds when the text input is focused and the pressed key matches a text-editing key (like Down arrow). Leader-prefixed keybinds like <leader>down (Ctrl+X → Down) were caught by this guard because the Down key matches input_move_down.

Fix: Add an exception for <leader>-prefixed keybinds so multi-key chords work while the prompt is focused.

Test Plan

• On bash, run a command targeting $HOME/some-path — should trigger external directory permission prompt
• With prompt focused, press Ctrl+X then Down — should navigate to subagent session