meta+z keybinding not working on macOS

Environment

• Claude Code version: 2.1.50
• OS: macOS (darwin)

Problem

User-defined meta+z keybinding in ~/.claude/keybindings.json is not working, despite being a valid configuration.

Keybindings configuration

{
  "context": "Chat",
  "bindings": {
    "meta+z": "chat:undo"
  }
}

Validation

• /doctor shows no keybinding configuration issues
• Configuration file syntax is valid
• The chat:undo action works fine with default bindings (ctrl+_, ctrl+shift+-)

Expected behavior

Pressing Cmd+Z while composing a message should undo the last text change, matching behavior in the Claude desktop app.

Actual behavior

Pressing Cmd+Z does nothing.

Notes

• Other default meta+ bindings work correctly (e.g., meta+p for model picker)
• This suggests the issue is specific to user-defined Command key bindings not being properly loaded/processed on macOS