A brief may carry an optional `## Threat Model` with one line per bullet,
`- Inside: <text>` or `- Outside: <text>`. Present and malformed (no such
bullet, another label or form, empty text, two sections) is
BRIEF_THREAT_MODEL_MALFORMED; absent is today's rule. No brief_version bump
(the ceremony / artifact_store precedent). Sections are found fence- and
comment-aware through intent-approval's new sectionTexts, so the validator
and the hash count the same sections; brief-validator exports
parseThreatModel for the reader.
The intent hash covers `## Threat Model` when present (two sections -> null
hash, as Intent and Goal), so an edited, added or removed threat model
makes the approval stale; a brief without one hashes exactly as before. The
stale message and the /trekplan halt table name the section.
/trekbrief offers the section in its question round when the task touches
a guard, a gate, untrusted input, secrets or publishing, writes it only
when given, shows it verbatim at the Phase 4h approval, and --approve reads
it out. The template documents it; brief-gate-coverage pairs the new code.
Part 2, step 2.1 of the E plan.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
