cctest: unify merge policy wording — recipe PRs are never agent-merged, both sides

Operator decision: no policy difference between cc-ci and recipe-maintainer. On
inspection ARM already agrees (recipe-upgrade-cron-all: 'PRs are reviewed and merged
manually by a human afterwards... never merges anything'; 'no human review in the
middle' = skip the mid-run plan confirmation only). Wrappers previously framed this
as a cc-ci override over ARM auto-merge flows — wrong reading; now stated as ONE
unified rule. /help conventions updated to match.

.opencode/skills/cctest-opencode-sync/SKILL.md

@@ -15,11 +15,11 @@ its shared swarm. Execute with the submodule as your working directory:
 configured on this host (`settings.toml` from `settings.toml.example`, sandbox/test instances),
 run `/cctest-intro` / `/cctest-setup-sandbox` first.
 
-**Policy overrides (cc-ci-orchestrator conventions win):**
-- Anything that would **merge a recipe PR or push a recipe main without review** requires
-  explicit operator opt-in per run — the cc-ci standing rule is recipe upgrade PRs are
-  operator-merged, and ARM skills that say otherwise (e.g. full-auto upgrade flows) do NOT
-  inherit blanket authorization here.
+**Unified policy (same as cc-ci — no differences):**
+- **Recipe PRs are NEVER merged by an agent.** Every flow ends at an open PR; the operator
+  reviews and merges. This is ARM's own rule too ("PRs are reviewed and merged manually by a
+  human afterwards — never pushes to upstream or merges anything"); ARM's "no human review in
+  the middle" wording refers only to skipping the mid-run plan confirmation, not to merging.
 - Never touch cc-ci infrastructure (the CI server, its swarm, `/root/*` clones, the weekly
   timers) from an ARM skill — cc-ci work goes through the cc-ci skills.
 - The submodule is **pinned**: don't commit into it from here; upstream ARM changes arrive via