39310d5b9a
- Node group CRUD operations with traffic-based filtering - Three grouping modes: average distribution, subscription-based, and traffic-based - Automatic and manual group recalculation with history tracking - Group assignment preview before applying changes - User subscription group locking to prevent automatic reassignment - Subscribe-to-group mapping configuration - Group calculation history and detailed reports - System configuration for group management (enabled/mode/auto_create) Database: - Add node_group table for group definitions - Add group_history and group_history_detail tables for tracking - Add node_group_ids (JSON) to nodes and subscribe tables - Add node_group_id and group_locked fields to user_subscribe table - Add migration files for schema changes