prompt-regression — Harness Regression Detection

After CLAUDE.md edits, rule changes, or new skill additions, harness behavior can silently regress. This skill runs a lightweight probe suite against the changed assets and compares outputs against saved baselines to surface regressions before they reach production.

Scope distinction

• harness-doctor: structural completeness (files, links, drift)
• prompt-regression: behavioral correctness — did the change alter expected AI response patterns?

Triggers

• /prompt-regression
• "prompt regression", "regression check", "regression test"
• "did my rule change break anything", "test harness changes", "verify harness behavior", "make sure my edit didn't change behavior"
• After significant CLAUDE.md edits or new skill commits