🗄️ 数据库ER图设计

erDiagram users ||--o{ user_profiles : has users ||--o{ user_tags : has users ||--o{ user_learning_progress : has users ||--o{ user_devices : has users ||--o{ user_sessions : has users ||--o{ user_auth_tokens : has users ||--o{ user_content_actions : performs users ||--o{ event_registrations : makes users ||--o{ event_submissions : submits users ||--o{ notifications : receives users ||--o{ comments : writes users ||--o{ user_relationships : follows users ||--o{ messages : sends users ||--o{ openclaw_users : connects_to contents ||--o{ content_chapters : contains contents ||--o{ content_resources : contains contents ||--o{ user_content_actions : affects contents ||--o{ content_analytics : generates categories ||--o{ contents : categorizes categories ||--o{ events : categorizes events ||--o{ event_tasks : has events ||--o{ event_registrations : receives events ||--o{ event_submissions : gets notifications ||--o{ notification_logs : logs comments ||--o{ comments : replies_to openclaw_users ||--o{ openclaw_projects : owns openclaw_users ||--o{ openclaw_sync_logs : generates