Customizable ASCII "working" animation

Summary

Allow users to configure the spinner/working indicator shown while Claude is processing a turn. Today the statusline is customizable but the active-work indicator is not.

Motivation

• Personalization / fun (themed spinners, project mascots, seasonal frames).
• Accessibility — some users want a calmer or higher-contrast indicator.
• Branding for teams that share Claude Code recordings or screenshots.

Proposed shape

A workingAnimation field in settings.json, e.g.:

{
  "workingAnimation": {
    "frames": ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"],
    "intervalMs": 80
  }
}

Or a script-based variant mirroring statusLine:

{
  "workingAnimation": { "command": "~/.claude/spinner.sh", "intervalMs": 100 }
}

Alternatives considered

• Statusline customization — doesn't cover the active-work indicator (re-renders per turn, not per frame).
• Wrapping the CLI in a TTY multiplexer — fragile and breaks input handling.

Additional context

Came up while looking for a way to swap the default spinner for an ASCII animation without modifying Claude Code itself.