- Extract SVD_CleanupPlayback for shared cleanup logic
- Called on demo end (SVD_PlaybackFrame) and manual stop
- Frees zombie client slots, saved configstrings, file handle
- Clears sv_demoplaying cvar so game module exits demo mode
- Hook into SV_Shutdown to clean up on server shutdown/map change
- Allows playing another demo after one finishes
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
