Canonical benchmark fixtures

This directory contains five deterministic failure scenarios for benchmark and self-healing-agent tests. Every fixture has the same contract:

• setup.sh <workdir> creates the failure state and exits successfully.
• expected.json describes the failure, expected outcome, and verification.
• teardown.sh <workdir> removes the state created by setup.

The scripts never write outside the work directory supplied by the caller. The fixture loader is available at bench/phase-b/orchestrator.py:

python3 bench/phase-b/orchestrator.py --list
python3 bench/phase-b/orchestrator.py --fixture dco-signoff --json

The fixtures are intentionally small and local-only: no network, credentials, or external services are required.