[Feature Request] Vim mode indicator placement control or JSON status integration

Bug Description
When vim input mode is enabled, the -- INSERT -- / -- NORMAL -- indicator renders on its own line below the custom statusLine output, using vertical space. Please consider either (a) a hideVimModeIndicator setting, or (b) including the current vim mode in the JSON piped to statusLine scripts, so users can render it inline with their own status info.

Environment Info

• Platform: linux
• Terminal: ghostty
• Version: 2.1.117
• Feedback ID: 7e96431a-bd7f-46de-b983-736b34af0fd4