v1.0.20 — AFK Manager + Sleep Manager

New modules:

• AFK Manager (afk-manager) — Detects idle players and marks them AFK after a configurable idle threshold. Broadcasts AFK/return status to all players. Optional: kick after extended idle, freeze movement while AFK, exempt creative/spectator players, and per-permission exemptions. Public API: isAfk(UUID) for other modules to query AFK status.
• Sleep Manager (sleep-manager) — Sleep voting system: skip the night when a configurable percentage (or flat count) of eligible players are in bed. No more waiting for every player to sleep. Broadcasts vote progress and skip notification. Clears weather on skip. Works on all server versions (no Paper-only APIs).