v3.10.0 - Per-group Auto-Scan Toggle

Features:
- Add auto_scan_enabled setting to toggle virus scanning per group
- New command: !room autoscan on/off for group admins
- Auto-scan defaults to ON for all groups

Fixes:
- Fix auto-archive to always save files to database for !rollup tracking
- Files now tracked even if MinIO upload fails

Database Migrations:
- 010_breakout_summary_columns.sql - Breakout room summary fields
- 011_auto_scan_setting.sql - auto_scan_enabled column