Optional TTY-only intro animation for interactive fest commands

[lancekrogers]

Summary

Consider a short, optional intro animation for fest's interactive TUI/CLI surfaces.

The goal is polish for first-run and interactive use, not decoration in agent/scripted runs.

Constraints

• Skip entirely when stdout is not a TTY, when output is piped, or when NO_ANIMATION/NO_COLOR/CI is set
• Keep it well under 500ms and never block a non-interactive command
• Prefer the existing Charm stack already in the repo; do not add ASCII-banner or sound dependencies for this
• Make it opt-in or easy to disable

Companion: camp issue for the same idea.