failure-taxonomy

Scope: Failure class meaning and action.
Audience: Operators and reviewers.
Guarantees: Each class maps to a clear response.
Non-Goals: Implementation detail.
Why: This doc exists to record its single responsibility for review.

Taxonomy

FailureClass	Meaning	User action
structural	The run violated declared structure or ordering.	Fix the flow manifest, dataset descriptor, or execution ordering.
semantic	Reasoning or evidence failed verification.	Correct claims, evidence, or policy expectations.
environmental	The execution environment drifted from the declared fingerprint.	Rebuild environment to match the plan.
authority	An unauthorized action or entropy source was used.	Remove or explicitly authorize the source.