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+# Tier 4 deploy canary
+
+This file exists so a long-lived pull request can carry a **fresh head SHA** for the
+post-deploy Tier 4 smoke check.
+
+The smoke sends a synthetic `check_suite` for this PR's head and then waits for a
+`Veripsa` check to appear on that exact SHA. It needs a PR that stays open and whose
+head can be moved cheaply.
+
+**Why this repository rather than `veripsa-dev`:** the durable webhook inbox drains
+per-account round-robin. A canary living in the same account as the busiest
+repositories waits behind that account's traffic, and a deploy's own restart makes
+the queue worse — so the canary timed out on deploys that had in fact succeeded.
+Moving it to a different account gives it its own fairness turn.
+
+Nothing here is product content. Do not treat the marker below as meaningful.
+
+Refreshed for deploy: initial