Implement parallel tool execution in AgentLoop, following the approach
used in Nanobot (_partition_tool_batches) and Zeroclaw (parallel_tools).
Key changes:
- partition_tool_batches(): group tool calls into batches based on
concurrency_safe flag. Safe tools run in parallel via join_all;
exclusive tools (e.g. bash) run in their own sequential batch.
- execute_tools(): now uses batching instead of flat sequential loop.
- CalculatorTool: add read_only() -> true so it participates in
parallel batches (it has no side effects, so concurrency_safe = true).
4 unit tests added covering: mixed safe/exclusive, all-safe single
batch, all-exclusive separate batches, unknown tool defaults.
- Added ContentBlock enum for multimodal content representation (text, image).
- Enhanced ChatMessage struct to include media references.
- Updated InboundMessage and OutboundMessage to use MediaItem for media handling.
- Implemented media download and upload functionality in FeishuChannel.
- Modified message processing in the gateway to handle media items.
- Improved logging for message processing and media handling in debug mode.
- Refactored message serialization for LLM providers to support content blocks.
- Removed internal history management from AgentLoop.
- Updated process method to accept conversation history as a parameter.
- Adjusted continue_with_tool_results to work with external history.
- Added OutboundDispatcher for handling outbound messages from MessageBus.
- Introduced InboundMessage and OutboundMessage structs for message handling.
- Updated Channel trait to include message handling and publishing to MessageBus.
- Refactored Session to manage chat histories instead of AgentLoop instances.
- Enhanced GatewayState to start message processing loops for inbound and outbound messages.
- Introduced a new CalculatorTool for performing various arithmetic and statistical calculations.
- Enhanced the AgentLoop to support tool execution, including handling tool calls in the process flow.
- Updated ChatMessage structure to include optional fields for tool call identification and names.
- Modified the Session and SessionManager to manage tool registrations and pass them to agents.
- Updated the OpenAIProvider to serialize tool-related message fields.
- Added a ToolRegistry for managing multiple tools and their definitions.
- Implemented tests for the CalculatorTool to ensure functionality and correctness.
