docs(1b): record the tests/_template deviation (enroll=copy-existing-recipe) per Adversary RL3/D5 advisory

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

DECISIONS.md

@@ -263,3 +263,11 @@ Architecture decisions and dead-ends. One line of rationale each. (§0, §8)
   LAST, in lockstep with the orchestrator updating `launch.sh` + restarting the watchdog — not
   unilaterally and not while a phase transition is pending. The Adversary likewise `git mv`s its own
   REVIEW files at the cutover (single-writer rule).
+
+## Phase 1b — recorded deviation: no `tests/_template/` dir (enroll = copy an existing recipe)
+Plan §3's repo layout lists a `tests/_template/` "copy-to-add-a-recipe" dir. It was **never created**
+(pre-1b; not introduced or removed by 1b) — instead the documented enroll flow in
+`docs/enroll-recipe.md` is **"copy an existing recipe's tree, e.g. `tests/custom-html/…`, then adjust
+`recipe_meta.py` + the per-recipe test files."** This satisfies D5's "small, repeatable, documented
+operation with no harness surgery" the same way (a concrete recipe is a better starting template than
+an abstract skeleton that can drift). Recording per the Adversary's RL3 D5 advisory; not a blocker.