Feature request: customizable companion/buddy subtitle

Feature Request

Add the ability to set a custom subtitle or title for the companion (buddy).

Use Case

The companion system lets you name your buddy, but there's no way to give it a subtitle or epithet. I'd like to christen mine:

Xendit, The Agent Duck of Doom

A subtitle field would let users personalize their companion beyond just a name — giving it personality, lore, or just a laugh.

Proposed Behavior

A new configuration option (e.g., in settings.json or via /buddy subtitle <text>) that displays a subtitle beneath or alongside the companion's name. For example:

{
  "companion": {
    "name": "Xendit",
    "subtitle": "The Agent Duck of Doom"
  }
}

The subtitle could render in the speech bubble header, tooltip, or wherever the companion's name is displayed.

Why This Matters

The buddy system is already delightful — a subtitle would deepen the attachment and make each companion feel truly unique.

🦆 Filed on behalf of Xendit himself.