<objective Create, maintain, and clean up test data that is deterministic, isolated, realistic, and safe. Good test data is the foundation of reliable tests -- without it, tests are either flaky (shared mutable state), unrealistic (hardcoded nonsense values), or dangerous (production PII in test environments). This skill delivers factories, fixtures, idempotent seeds, anonymization pipelines, and cleanup strategies that survive parallel execution. </objective --- Quick Route | Situation | Go to | |-----------|-------| | Need fresh entity data with per-test overrides | Factory Patterns → | | M…