## Adversarial synthesis

**Synthesis contract (single source).** Collect all N reviewers' findings
tables — each already in the reviewer contract's fixed format above
(a `provenance` note records which reviewer/source produced each row) — and:

- **Dedupe by `file:line` + axis** (two genuinely different findings on the
  same line, different axis, stay separate). Identical findings from multiple
  reviewers collapse into **one** row.
- Annotate each synthesized row with a `Reviewers n/N` column — how many of
  the N flagged it — as a confidence signal.
- **Inclusion threshold = ≥1 reviewer.** A finding any single reviewer raised
  enters classification normally; there is no majority/quorum gate to include a
  finding — a real defect only one sharp reviewer caught must not be dropped.
- **Forbidden — never**, while synthesizing: dropping a finding, downgrading
  its severity, reclassifying it, or re-litigating whether it's real. The
  fusion step's only job is to synthesize; disputing a finding's validity
  happens later, in the normal classification and outcome-routing steps that
  consume the synthesized table — never during the fusion itself.
- **Externally-produced reviews** (not spawned by this run) are accepted into
  the fusion **only if they already arrive in the reviewer contract's fixed
  table format**. Normalizing free prose into that format is the contributing
  conversation's job, not the fusion step's — it converts to the table first.
- The synthesized table then flows through the rest of the process above —
  classification, debt transform, manual verification, outcome routing —
   producing the same fixed-format report ending `Decision:
   REVIEW-PASS | REVIEW-FAIL | NEEDS-DECISION` (D10).

Prompts use **synthesize/fuse** language, never repository merge terminology —
this contract fuses review tables; it performs no repository merge.

**`--synthesize` mode.** `/review-change --synthesize` is the direct entry
point for the synthesis contract above — it starts **at the fusion step**,
skipping the N-reviewer spawn: pass it N pasted findings tables (each already
in the reviewer contract's fixed format), and it runs the synthesis contract,
then the rest of the process, to the same fixed report ending `Decision:
REVIEW-PASS | REVIEW-FAIL | NEEDS-DECISION`. This is how a manual orchestrator — one that ran the N reviewer
conversations by hand via the Portability paste blocks — hands the results
back to this skill for fusion, without re-authoring the dedupe/threshold/
forbidden rules itself: the mode consumes the single synthesis contract above,
never a second copy of it.

**Cadence — once per unit.** The adversarial run (spawn or `--synthesize`)
happens **once per unit, at the mandatory terminal `review-change`** (the pass
before `Hardening & PR` — see *Review checkpoint & finishing a unit* in
`execute-phase`), where the adversarial recommendation checklist is evaluated. The
one stated exception, not a cadence of its own: a phase touching a sensitive
surface (auth, payments, destructive migrations, secrets, CI config) may earn
an **early** adversarial pass scoped to just that phase's diff — still a
single extra event, not a recurring checkpoint. **Boundary with `#77`** (the general review-checkpoint cadence redesign):
this section owns *where* the adversarial mode runs (the terminal review, plus
the sensitive-phase exception); `#77` owns the general every-N-phases
checkpoint interval — neither issue's change edits the other's sentences.