Diagnose

Find the mechanism that produces a bug. This skill diagnoses; it does not implement the fix unless the user explicitly asks for implementation after the diagnosis.

When invoked by triangulate-diagnosis, use the provided lens and return the exact Diagnosis Report shape from triangulate-diagnosis/REFERENCE.md.

Inputs

Accept any of:

• A bug report, error message, failing behavior, screenshot, log, or pasted stack trace.
• Reproduction steps or a failing test.
• A local issue, spec, ticket, PR, commit, branch, or file path already available in context.
• A diagnostic lens from triangulate-diagnosis: repro-first, data-flow, or recent-change / environment.