Allow configuring companion (buddy) speech bubble display duration

Feature Request

The companion/buddy speech bubble disappears too quickly for some users. It would be great to have a configurable setting to control how long the speech bubble lingers before fading out.

Use Case

I read slowly (non-native English speaker) and often can't finish reading the companion's comment before it disappears. There's currently no way to adjust this.

Proposed Solution

Add a setting like companionBubbleDuration (in seconds) to control how long the speech bubble stays visible. For example:

{
  "companionBubbleDuration": 10
}

A value of 0 or "persistent" could mean it stays until the next user action.

Current Workarounds

• /buddy mute / /buddy unmute — but this is all-or-nothing, not a real solution.

Environment

• Claude Code CLI (macOS)