testing-fieldbook

# Testing the fdeops fieldbook Everything here is local-only and network-free. No credentials are needed. ## Devin Secrets Needed None. ## Sandbox harness (use for every case) ```bash H=$(mktemp -d); ROOT="$H/fde-engagements" HOME="$H" FDEOPS_ENGAGEMENTS_ROOT="$ROOT" node bin/fde.js resume --init client-a ``` Rules learned the hard way: - **Create decoy fixtures FIRST.** The absence of a directory proves nothing. Always make a second engagement (`client-b`) plus a `realclient` decoy and a `.registry` binding, then compare sorted `sha256sum` manifests of every non-target engagement before/after. A case passes only if every engagement the operator did not name is byte-identical. - `fde doctor` **exits 1 by design** when it finds hygiene issues. Never treat nonzero doctor as a test failure by itself. - Strip ANSI before grepping output; colored prompts/markers silently break naive greps. - `npm run check` runs gates **and** tests; `npm test` alone runs only tests. - Regression floor: v3.10.3 → 97/97; v3.10.4 → **103/103**, then **107/107** once the non-regular and slug guards landed. `npm run check` exit 0. Check the current floor rather than assuming. - **Wrap every single CLI/hook invocation in `timeout 15` regardless.** Non-regular-file shapes have repeatedly re-introduced blocking reads/writes; without `timeout` the whole matrix stalls instead of reporting exit 124, and a regression here is invisible. ## Engagement resolution — the part most likely to b...