refactor: unify impl operation gates and correction verification

harness/tests/common/impl_contract_docs.py

@@ -0,0 +1,17 @@
+"""Read only the explicitly required workflow reference for canonical impl skills."""
+from pathlib import Path
+
+NAMES = {"gitea-issue-implementation", "gitea-issue-rework"}
+REQUIRED = "Required reference: [workflow](references/workflow.md)"
+
+def read_contract(path):
+    path = Path(path)
+    text = path.read_text(encoding="utf-8")
+    if path.name == "SKILL.md" and path.parent.name in NAMES:
+        if REQUIRED not in text:
+            raise AssertionError("impl skill does not require its canonical workflow reference")
+        reference = path.parent / "references/workflow.md"
+        if reference.is_symlink() or not reference.is_file():
+            raise AssertionError("canonical workflow reference missing or symlinked")
+        text += "\n" + reference.read_text(encoding="utf-8")
+    return text