When the LLM fails to emit a tool_call XML block, the feedback now includes
the exact XML format expected with a concrete example for json.validate.
This helps smaller models understand the exact output format required.
- Add onToken callback option to IDualAgentOptions interface
- Add onToken property and setOnToken method to DriverAgent
- Wire up streaming in startTask and continueWithMessage methods
- Pass source identifier ('driver'/'guardian') to onToken callback
