- Implemented HelpCommandHandler to handle the /help command.
- Added CommandMetadata struct to store command metadata.
- Registered new command handlers for GetCurrentSession, ListSessions, LoadSession, and SwitchSession.
- Updated existing command handlers to provide metadata for help command.
- Removed deprecated SessionQueryCommandHandler.
- Added new command handlers for listing sessions and loading sessions.
- Introduced `TaskConfig` struct to manage task-related configurations.
- Implemented `TaskTool` for creating and managing subagents for complex tasks.
- Added `TaskSession` and `TaskRepository` for handling task sessions and persistence.
- Created `DefaultSubAgentRuntime` to execute tasks with timeout and history support.
- Enhanced `ToolContext` to include `subagent_description` for better context tracking.
- Implemented error handling for task execution and session management.
- Updated `ToolRegistryFactory` to register task tools conditionally based on configuration.
- Added prompt builders for subagent tasks to improve interaction clarity.
- Added topic management capabilities, allowing users to create, switch, and query topics within sessions.
- Updated command structure to include new commands: SwitchSession and GetCurrentSession.
- Introduced TopicRecord for managing topic data in the storage layer.
- Modified session handlers to accommodate topic operations, including listing and loading topics.
- Enhanced database schema to support topics, including new tables and relationships.
- Updated input adapters to recognize new commands and handle topic-related actions.
- Improved logging for session and topic operations to aid in debugging and monitoring.
