[Feature Request] Add option to hide default vim mode indicator in custom status line

Bug Description
Feature Request: Option to hide default vim mode indicator

I've configured a custom status line that displays vim mode alongside other info (user, directory, git branch, model, context). This creates duplication since the default "-- INSERT --" indicator still shows below.

Current behavior:

  name  repo  branch  INSERT  Opus 4.5 ctx:54%
  -- INSERT --

Desired behavior:
A setting like hideVimModeIndicator: true in settings.json that hides the default indicator when users have a custom status line showing vim mode.

Use case:
Custom status lines can already access .vim.mode from the input JSON, so users can display vim mode in their preferred style/position. Having a way to disable the default indicator would allow for a cleaner, unified status bar experience.

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.12
• Feedback ID: 5270aabe-c77d-410d-81eb-3744f4cf24ec

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/remikalbe/.local/share/claude/versions/2.1.12 (expected in multi-process scenarios)\n    at HZR (/$bunfs/root/claude:3279:2091)\n    at aYA (/$bunfs/root/claude:3279:1202)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-01-19T07:11:22.579Z"}]