- Added MySQL database implementation with connection settings and session management.
- Introduced a new AstrBotMySQLSettings class for configuration.
- Updated database helper functions to support both SQLite and MySQL.
- Enhanced platform statistics retrieval with time series data for both database types.
- Refactored existing SQLite methods to align with new database structure and functionality.
closes: #3848
* refactor: message storage format of webchat
* refactor: update image and record handling in webchat event processing
* fix: thinking placeholder in webchat
* feat: supports file upload in webchat
* feat: supports to delete attachments when webchat session is deleted
* perf: improve performance of file downloading
* refactor: remove unused import in chat route
* feat: add message timestamp formatting and localization support in chat
* fix: handle missing filename in file upload for chat route
* feat: enhance file handling in chat and webchat, supporting video uploads and improved attachment management
* fix: update property name for embedded files in message handling
* fix: compute variable errors after uninstalling plugins
* feat: supported for reply message and standarlize the message param
* fix: ensure message actions are displayed for the last message in the list
- Added WebChatSession model for managing user sessions.
- Introduced methods for creating, retrieving, updating, and deleting WebChat sessions in the database.
- Updated core lifecycle to include migration from version 4.6 to 4.7, creating WebChat sessions from existing platform message history.
- Refactored chat routes to support new session-based architecture, replacing conversation-related endpoints with session endpoints.
- Updated frontend components to handle sessions instead of conversations, including session creation and management.