check-role-discipline is red on main at 988482882: my merge commit did not name its task branch

Row: ENG-ROLE-DISCIPLINE-988482882

check-role-discipline.py is RED on main at 988482882:

ERROR: 988482882: repository change (include/vllm/v1/worker/gpu/prepare_inputs.h,
include/vllm/v1/worker/gpu/runner.h, src/vllm/v1/worker/gpu/prepare_inputs.cpp,
src/vllm/v1/worker/gpu/runner.cpp, ... (+2)) reached main without arriving on a
task branch.

Cause: my merge commit's message, nothing about the content. Landing #2991 I
brought main into my integration branch with git merge --no-ff --no-edit origin/main and did not amend the result, so it carries git's default
Merge remote-tracking branch 'origin/main' into land3. arrives_via_row_pr
accepts a merge whose own message matches row/[A-Za-z0-9_.-]+ or a PR
reference, or whose merged-in commits do; land3 is neither, and the second
parent 4269469da is itself a merge: origin/main into the A2-4 optimistic correction that names neither.

The flagged files are NOT mine and did not arrive through me. They came from
4269469da, another session's work already on main before my push. They appear
"new" only because merging main INTO my branch makes my branch the first parent,
so main's own content shows up on the first-parent walk as if this commit
introduced it.

Not repairable in place. The fix is a commit message and main is never
force-pushed. Advancing scripts/ci-enforcement-floor.txt past it would make the
gate green by widening its scope to hide my own error, which AGENTS.md forbids
and which I am not doing.

The rule that prevents a repeat, worth having written down because I got it
right four times today and wrong once: when merging main into an integration
branch before pushing, the merge commit must be AUTHORED and name the row branch
or PR it is landing. --no-edit is what fails. I amended the earlier ones and
missed this one.

Blast radius, stated honestly rather than guessed: a PR's CI walks
BASE..HEAD from its own base, so a PR branched off current main does not
include this commit. The push lane on main does walk from the last gated
commit and would include it, and CI does not run on direct pushes to main
anyway. I have not established whether any other contributor's run is reddened
by it; if one is, that is the harm and this issue owns it.

Start with check-role-discipline.py and the ENG-ROLE-DISCIPLINE-988482882 report, then read the merge-handling guidance in AGENTS.md. Reproduce the behavior around commit 988482882 and parent 4269469da, checking how first-parent traversal treats files already on main. Done means the gate distinguishes pre-existing main content from an unnamed landing merge without advancing scripts/ci-enforcement-floor.txt to hide the failure.