claim(2w): WC5 promote-on-green-cold proven — green cold run advances canonical (1.10.0→1.11.0); --quick never promotes; only cold advances

should_promote_canonical (enrolled+green+cold+latest) + promote_canonical
(re-seed canonical at green-verified latest, snapshot+registry, old known-good
replaced only on green). +5 unit (70 pass). Live: custom-html canonical advanced
1.10.0+1.28.0 → 1.11.0+1.29.0 via a full green cold run; snapshot refreshed; idle;
per-run app torn down. WC6 nightly sweep next.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/unit/test_promote.py

@@ -0,0 +1,49 @@
+"""Unit tests for the WC5 promote-on-green-cold gate (run_recipe_ci.should_promote_canonical).
+
+Pure predicate. The live promote (deploy canonical at latest → snapshot → registry) is proven on
+custom-html (W3). is_enrolled is monkeypatched so the test doesn't depend on which recipes are
+enrolled on disk.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", ".."))
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "runner"))
+import run_recipe_ci as rr  # noqa: E402
+from harness import canonical  # noqa: E402
+
+
+def _enrolled(monkeypatch, val):
+    monkeypatch.setattr(canonical, "is_enrolled", lambda r: val)
+
+
+def test_promote_when_enrolled_green_cold_latest(monkeypatch):
+    _enrolled(monkeypatch, True)
+    # green (overall 0), cold (quick False), latest (ref None) → promote
+    assert rr.should_promote_canonical("custom-html", None, 0, quick=False) is True
+    assert rr.should_promote_canonical("custom-html", "", 0, quick=False) is True
+
+
+def test_no_promote_when_not_enrolled(monkeypatch):
+    _enrolled(monkeypatch, False)
+    assert rr.should_promote_canonical("hedgedoc", None, 0, quick=False) is False
+
+
+def test_no_promote_when_red(monkeypatch):
+    _enrolled(monkeypatch, True)
+    assert rr.should_promote_canonical("custom-html", None, 1, quick=False) is False
+
+
+def test_no_promote_when_quick(monkeypatch):
+    # --quick never promotes (the canonical advances ONLY via cold)
+    _enrolled(monkeypatch, True)
+    assert rr.should_promote_canonical("custom-html", None, 0, quick=True) is False
+
+
+def test_no_promote_on_pr_head(monkeypatch):
+    # a PR `!testme` carries REF=PR-head → must NOT advance the canonical to a PR's code
+    _enrolled(monkeypatch, True)
+    assert rr.should_promote_canonical("custom-html", "abc123def", 0, quick=False) is False