Worklog for task "Implement a custom AI dialog engine with dynamic scenarios"

Runtime Foundation: Streaming Execution and Cancellation

A low-level execution mechanism has already been implemented for the upcoming proprietary dialogue runtime:

• a shared ExecutionContext with a run identifier, abort signal, and event delivery;
• a streaming NDJSON contract POST /api/chat;
• correct started/delta/done/error/cancelled states;
• explicit execution cancellation as well as cancellation on disconnect/timeout/shutdown;
• independence of parallel runs;
• input and response size limits.

The HTTP layer has been re-verified with 8/8 tests.

This does not mean the scenario engine is ready: the declarative scenario model, nodes/branching, scenario versioning, persistent dialogue state, message idempotency, and atomic transitions are not yet implemented.