[Bug] voice:pushToTalk keybinding in keybindings.json not triggering voice recording

Bug Description

voice:pushToTalk in keybindings.json does not work on Ubuntu.

$ cat .claude/keybindings.json 
{
  "$schema": "https://www.schemastore.org/claude-code-keybindings.json",
  "$docs": "https://code.claude.com/docs/en/keybindings",
  "bindings": [
    {
      "context": "Chat",
      "bindings": {
        "ctrl+up": "voice:pushToTalk",
        "space": null
      }
    }
  ]
}

(pressing ctrl+up)

$ cat -v
^[[1;5A

❯ /voice                                                                        
  ⎿  Voice mode enabled (hold). Hold ctrl+↑ to record.                      

but Ctrl+Up does NOT start the voice recording!

in fact, holding space down still starts the voice recording, but I can't stand having to do that.

It used to weeks ago, but stopped working some versions back.

It's not just a problem with ctrl+up. No key specifier in this file has any effect.

Other actions like chat:externalEdit do work in this file.

Ubuntu 24.04 gnome-terminal

Environment Info

• Platform: linux
• Terminal: gnome-terminal
• Version: 2.1.126
• Feedback ID: cb1339c8-c607-457a-b101-9915c8ad654e

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /home/USERNAME/.local/share/claude/versions/2.1.126 (expected in multi-process scenarios)\n    at n68 (/$bunfs/root/src/entrypoints/cli.js:2770:2177)\n    at sM6 (/$bunfs/root/src/entrypoints/cli.js:2770:1257)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-03T03:22:25.392Z"}]