dev-diagnoselisted

# Dev Diagnose Structured debug loop for bugs with non-obvious causes. ## Phase 1 — Reproduce Before anything else: confirm the bug is reproducible. 1. State the exact failing behaviour (symptom, not guess). 2. Write the minimal reproduction: one test, one command, one curl — whatever isolates the failure. 3. If you cannot reproduce it, stop. Ask for steps to reproduce before continuing. ## Phase 2 — Minimise Strip the reproduction down to its smallest possible form. - Remove all code not needed to trigger the failure. - Remove all data not needed to trigger the failure. - If the bug disappears during minimisation, the removed code is the cause — inspect it. ## Phase 3 — Hypothesise Generate 3–5 distinct hypotheses. For each: - State the assumed mechanism. - State what evidence would confirm it. - State what evidence would rule it out. Rank by likelihood. Do not skip low-probability hypotheses — they catch blind spots. ## Phase 4 — Instrument Add targeted observability to confirm or rule out each hypothesis: - Prefer log statements at decision points over debugger stepping. - One hypothesis per instrument run — do not change multiple things at once. - Record what you observed and which hypotheses it eliminates. ## Phase 5 — Fix Once the root cause is confirmed: 1. Write the fix as the minimal change that addresses the root cause. 2. Do not refactor surrounding code as part of the fix. 3. Verify the reproduction from Phase 1 no longer fails. 4. Check for other