📚 Accio command guide: document the IRC and Partyline spells ✨
Chart the Mediabot 3.5 and 3.6dev wiki corridors 🗺️📚 Reorganize the GitHub wiki around a clear first-install journey for stable 3.5 and the active 3.6dev line. Document all 243 built-in commands with the ! prefix, separate global roles from per-channel levels, describe all 34 chansets, and add current operational guides for mbweb, radio, migrations and systemd. Remove obsolete 3.3/3.4dev material, duplicated procedures and legacy command examples while preserving focused maintainer references.