Custom keybinding for ctrl+v doesn't override default chat:imagePaste

Description

Setting ctrl+v to a custom action in ~/.claude/keybindings.json does not override the default chat:imagePaste binding. The default action still fires ("No image found in clipboard"), while other custom bindings (e.g. ctrl+g) work fine.

keybindings.json

{
  "$schema": "https://www.schemastore.org/claude-code-keybindings.json",
  "$docs": "https://code.claude.com/docs/en/keybindings",
  "bindings": [
    {
      "context": "Chat",
      "bindings": {
        "ctrl+v": "chat:externalEditor",
        "ctrl+g": "chat:externalEditor"
      }
    }
  ]
}

Expected behavior

ctrl+v should trigger chat:externalEditor.

Actual behavior

ctrl+v triggers the default chat:imagePaste ("No image found in clipboard"). ctrl+g works correctly.

Version

Claude Code 2.1.92, macOS, iTerm2