docs(agents): a cherry-pick keeps its source's author, and the check is per own commit (improvise-1xfb.3)

The wrapper's contract drops cherry-pick, because git ignores
GIT_AUTHOR_NAME there, and rule 8's cherry-pick -x should keep who wrote
the commit. A new case asserts it. The pre-push check now asks that every
commit you made names your actor, since a stacked or cherry-picked commit
keeps its own author. Answers the Codex P2 and the review on PR #310.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VdfEGXA7aJ6ftMsCc9PJze

.agents/skills/wave/agent-rules.md

@@ -221,8 +221,7 @@ out on purpose:
   (matching BEADS_ACTOR)" (2026-09-25; improvise-1xfb.3). Make every commit
   through the wrapper, merge commits included:
   `BEADS_ACTOR=<your actor> scripts/agent-git commit …`, and the same for
-  `merge` or `cherry-pick`. The wrapper sets the author name for that one
-  command, and it refuses (exit 2) when `BEADS_ACTOR` is unset or empty. It
+  `merge`. The wrapper sets the author name for that one command, and it refuses (exit 2) when `BEADS_ACTOR` is unset or empty. It
   reads `BEADS_ACTOR` from its own environment, so the prefix works in a shell
   that keeps nothing between commands.
   - **The author email, the committer and the `Co-Authored-By` trailer stay as
@@ -235,8 +234,12 @@ out on purpose:
     `context/test-evidence/tooling.md`.
   - A plain `git commit --amend` keeps the author it amends, so amend with
     plain git or with the wrapper.
+  - **A cherry-pick keeps its source's author**, through the wrapper or not:
+    git ignores `GIT_AUTHOR_NAME` there. That is right, because rule 8 allows
+    only `cherry-pick -x` of commits that keep whoever wrote them.
   - Before you push, check `git log --format='%an <%ae> | %cn' <pinned
-    SHA>..HEAD`. Every line must name your actor.
+    SHA>..HEAD`. Every commit **you made** must name your actor. A
+    cherry-picked commit, or one from a PR you stack on, keeps its own author.
   - **The format is a proposal.** `Claude (<BEADS_ACTOR>)` is the default
     proposed on improvise-1xfb.3's PR. The user may change it there. The format
     lives in `scripts/agent-git` and nowhere else.

context/test-evidence/tooling.md

@@ -1789,7 +1789,16 @@ commit reads `Claude (t) <o@x> | Owner`. The same probe showed that a merge
 takes `GIT_AUTHOR_NAME` too, and that a plain `--amend` keeps the author it
 amends.
 
-**Rivals.**
+**A cherry-pick keeps its source's author** (Codex P2 and the review on PR
+#310). The first version of the rule listed `cherry-pick` among the wrapper's
+subcommands, but git ignores `GIT_AUTHOR_NAME` there. That is the behaviour
+this repo wants, since rule 8 allows only `cherry-pick -x` of commits that keep
+their own author. So the contract names only `commit` and `merge`. The case "a
+cherry-pick keeps its source's author" picks a commit authored `Claude
+(agent-b2)` with the wrapper set to `agent-a1`, and asserts `agent-b2`. A pick
+that failed would leave the owner-authored base at HEAD and fail the case too.
+
+**Rivals** (run against the first eleven cases).
 - **`exec git -c user.name="Claude ($BEADS_ACTOR)" "$@"`**: 10 passed,
   1 failed, "the committer is untouched" (got `Claude (agent-a1)`).
 - **The refusal removed** (`if false`): 7 passed, 4 failed. They are "an unset

scripts/agent-git

@@ -5,7 +5,7 @@ set -euo pipefail
 
 if [ -z "${BEADS_ACTOR:-}" ]; then
   echo 'agent-git: BEADS_ACTOR is unset; refusing to author as the owner' >&2
-  echo 'usage: BEADS_ACTOR=<actor> scripts/agent-git commit|merge|cherry-pick ...' >&2
+  echo 'usage: BEADS_ACTOR=<actor> scripts/agent-git commit|merge ...' >&2
   exit 2
 fi
 

scripts/agent-git-test.sh

@@ -50,6 +50,12 @@ BEADS_ACTOR=agent-a1 "$RUN" merge -q --no-edit side
 same "a merge commit is authored by the agent" 'Claude (agent-a1)' "$(git log -1 --format=%an)"
 same "the merge has two parents" 2 "$(git log -1 --format=%P | wc -w | tr -d ' ')"
 
+# A cherry-pick keeps its source's author, whatever the wrapper sets.
+git checkout -q -b pick "$base"
+BEADS_ACTOR=agent-a1 "$RUN" cherry-pick -x --allow-empty "$(git rev-parse side)" > /dev/null 2>&1
+same "a cherry-pick keeps its source's author" 'Claude (agent-b2)' "$(git log -1 --format=%an)"
+git checkout -q -
+
 # git's own failure is passed through, not swallowed.
 BEADS_ACTOR=agent-a1 "$RUN" commit -q -m nothing-staged > /dev/null 2>&1
 rc=$?