[Feature Request] Plan/Permission "edit in editor" shortcut should be rebindable via keybindings.json

Bug Description
The "edit in editor" shortcut in the plan-acceptance dialog (ExitPlanMode / "Here is Claude's plan… Ready to code?") is hardcoded to Ctrl+G and isn't rebindable via keybindings.json.

The prompt editor (chat:externalEditor) honours keybindings.json fine - I remapped it off Ctrl+G to avoid a conflict with my terminal multiplexer (Zellij uses Ctrl+G for lock/unlock). But the plan dialog renders the shortcut as a literal "ctrl+g" rather than via the rebindable action, so Zellij swallows the key and I can never trigger plan-edit.

Request: route the plan/permission "edit in editor" shortcut through the existing chat:externalEditor action (or add a rebindable action like confirm:externalEditor) so it respects keybindings.json. The same hardcoded Ctrl+G also appears in the "edit agent" and "edit script in $EDITOR" dialogs.

Version: claude-code 2.1.175

Environment Info

• Platform: darwin
• Terminal: kitty
• Version: 2.1.175
• Feedback ID: f43998a3-63fb-491a-822a-87dad20c81f2