debug

A bug is a falsified assumption. Find the assumption, falsify it deliberately, observe the divergence, narrow until one line owns the lie. ## When to Apply / NOT Apply: test fails and cause unclear; production stack trace; intermittent / flaky behavior; wrong output without crash; regression after known commit window; heisenbug. NOT apply: performance regression with correct outputs; security defect; symptom obvious from one-line read; architectural confusion. ## Anti-patterns - **Shotgun debugging**: editing several files hoping one fixes it. - **Print-and-rerun**: adding logs without a target observation. - **Premature fix**: patching symptom before isolating root cause. - **Ignoring the trace**: stack frames are evidence. - **Changing two variables at once**: defeats falsification. - **Deleting the failing test**: capturing the bug is the asset. - **Confirmation bias**: interpreting ambiguous evidence as supporting the current hypothesis. Before declaring confirmed, ask: "What would disprove this?" - **"It works now, move on"**: if the WHY cannot be explained -- the full causal chain -- the root cause is not confirmed. A coincidental fix is not a fix. - **Weak prediction**: a prediction that restates the hypothesis adds no information. A good prediction names something not yet observed in a different code path or scenario. Read `references/anti-patterns.md` before forming hypotheses. Stop and re-examine if the internal monologue contains "quick fix for now," "this sh...