Debug

Localize (which layer?) then instrument (prove hypothesis with logs). Cursor debug mode expects NDJSON at applications/.cursor/debug-<sessionId>.log.

When to Use

• Owning layer unknown; cross-layer repro needed
• Cursor debug mode, NDJSON at .cursor/debug-*.log, compose mount/env
• Instrumentation to prove or disprove a hypothesis

Not for: new features (issues-format.md), tests/CI (testing), read-only hunches (investigate), prod/k8s logs (k8s project-local skill — see docs/tiers.md).

Craft principles