docs(open-pr): watch the regional Cloud Builds, not the global list

.claude/skills/open-pr/SKILL.md

@@ -183,10 +183,19 @@ When such paths merged, watch until the build succeeds — a red Cloud
 Build means production did NOT update even though the PR was green:
 
 ```bash
-gcloud builds list --limit 3
-gcloud builds log <id>   # on failure
+gcloud builds list --region=europe-west4 --limit 3 \
+  --format='table(id,status,createTime,substitutions.TRIGGER_NAME,substitutions.SHORT_SHA)'
+gcloud builds log --region=europe-west4 <id>   # on failure
 ```
 
+The `--region` flag is load-bearing: the `deploy-app` / `deploy-api`
+triggers are **regional** (europe-west4), and the global `gcloud builds
+list` answers with a handful of months-old global builds — all
+`SUCCESS`, none from today — which reads like "nothing was triggered"
+while both deploys are already done (2026-08-28, #10808 follow-through:
+a 20-minute poll on the global list never saw the builds). Match the
+`SHORT_SHA` column against the merge commit before trusting a row.
+
 ## Gotchas
 
 - **`isOutdated` ≠ `isResolved`.** A fix-push can outdate a Copilot

CHANGELOG.md

@@ -211,6 +211,11 @@ aggregate instead: an italic *Catalog* line at the end of the version section an
 
 ### Changed
 
+- **`open-pr` skill: the post-merge Cloud Build watch names the region** — `gcloud builds
+  list` without `--region=europe-west4` answers with months-old global builds (all `SUCCESS`,
+  none from today), which reads like "nothing was triggered" while both regional deploys are
+  already done; the #10808 follow-through polled that list for 20 minutes. The command now
+  carries the region and a `SHORT_SHA` column to match against the merge commit (#10809).
 - **`babysit-pipeline`'s gap-backfill guidance corrected against a completed run** — the
   section shipped in #10628 was written mid-backfill and three of its claims did not
   survive the rest of it. The halt-on-cluster threshold counted raw failed runs, but one