atelier brief: push to master per task, and ATELIER-COMPLETE closes the run

plugins/EXTRACT-ATELIER-PROMPT.md

@@ -15,10 +15,9 @@ Paste everything below the line into a fresh agent.
 You are extracting **Atelier** out of `~/officer-dev/dockers/officer-atelier` and into an Officer plugin,
 the way `music`, `offscale` and `gitea` were extracted before it.
 
-**Work in a git worktree, not the main checkout.** Another agent may be working in
-`/home/pastilhas/officer-dev/platform` tonight. On 2026-08-20 two agents with bypassed permissions ended
-up in one working tree and only avoided losing work because one of them noticed and stopped. Do not
-arrange that again:
+**Work in a git worktree, not the main checkout.** Another agent is watching
+`/home/pastilhas/officer-dev/platform` and pulling into it as you push. Two processes in one working tree
+is how work gets lost — on 2026-08-20 it nearly did.
 
 ```
 git -C /home/pastilhas/officer-dev/platform worktree add /home/pastilhas/officer-dev/atelier-work -b atelier-plugin
@@ -26,6 +25,20 @@ git -C /home/pastilhas/officer-dev/platform worktree add /home/pastilhas/officer
 
 Everything below happens in `~/officer-dev/atelier-work`.
 
+**Push every commit straight to master**, from the worktree:
+
+```
+git push origin HEAD:master
+```
+
+The branch is only there to keep your files out of the other checkout. Master is what is being reviewed.
+Push after every task — a reviewer reading five small commits can tell you what went wrong on the second
+one; nobody can do that with one commit at the end.
+
+**Your final commit message must contain `ATELIER-COMPLETE` on its own line**, and no earlier commit may
+contain that string. It is the signal that the run is finished and the review can start. Do not use it to
+mean "this part is done".
+
 ## Read first, in this order
 
 1. **`plugins/EXTRACTING-A-PLUGIN.md`** — the runbook and the authority. Read "What changed on