agent-lab/docs/plans/todo-40-chat-message-stream-audit.md

Todo 40: Chat Message Stream Audit Boundaries

Goal

Add audit events around ChatAgent visible message streaming so replay can show when user-visible text starts and when it ends.

Plan

1. Emit chat_message_stream_started before the first message_delta reaches the output queue.
2. Emit chat_message_stream_finished after the model stream ends and before chat_agent_response.
3. Keep chat_agent_response as the complete aggregated visible ChatAgent text for that call.
4. Add readable Audit Replay summaries for the new events.

Verification

• uv run pytest tests/test_debug_runtime.py::test_runtime_audits_chat_message_stream_boundaries_in_output_order -q
• uv run pytest tests/test_debug_runtime.py::test_runtime_emits_audit_events_and_backend_logs -q
• uv run pytest tests/test_websocket_api.py::test_static_app_handles_audit_messages -q
• uv run pytest
• node --check src/agent_lab/presentation/static/app.js
• git diff --check