feature: GenerationLog option support in nemoguardrails with colang 2

Did you check the docs?

• I have read all the NeMo-Guardrails docs

Is your feature request related to a problem? Please describe.

Currently, the GenerationOptions class includes a log option with fields like activated_rails, llm_calls, internal_events, and colang_history. These work in colang 1.x, but using them with Colang 2.0 raises a ValueError due to lack of support. This limits the or analyze the system when using newer Colang flows.

We rely on this logging capability to capture product-level metrics (e.g., which rails were activated, which certain actions were triggered, LLM calls, etc.) that are essential to our observability stack. Losing this in Colang 2.0 limits our ability to track user interactions, rail usage, and model behavior.

Describe the solution you'd like

We’d like support for the log option in GenerationOptions to be added for Colang 2.0.

Describe alternatives you've considered

Describe alternatives you've considered
Reverting to Colang 1.x.

Additional context

activated rails:

if (
options.log.activated_rails
or options.log.llm_calls
or options.log.internal_events
or options.log.colang_history
):
raise ValueError(
"The log option is not supported for Colang 2.0 configurations."
)

Start at the GenerationOptions log handling and the Colang 2.0 validation that raises the shown ValueError. Trace how activated_rails, llm_calls, internal_events, and colang_history are handled in Colang 1.x, then determine what tests cover the equivalent Colang 2.0 behavior. Done means these logging options work for Colang 2.0 without the unsupported-option error.