Diagnose

This is a structured debugging protocol that forces you to build a fast feedback loop before you do anything else. It walks you through constructing a failing test, curl script, or headless browser harness that proves the bug exists, then guides you through hypothesis generation, targeted instrumentation, and regression testing. The core insight is that 90% of debugging is having a two-second deterministic repro. It explicitly tells you to generate three to five falsifiable hypotheses and show them to the user before testing, which cuts through the usual thrashing. Use it when someone reports a bug or performance regression and you need disciplined structure instead of staring at code. The post-mortem step feeds architectural problems back to improvement skills, which is smart.