fix: reject duplicate keys in execution catalogs

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a0726e-5232-73f2-aaca-2c05ceb62efb

README.md

@@ -17,6 +17,11 @@ assignment / channel / activity
 
 ## Profiles
 
+Catalog YAML rejects duplicate mapping keys, including collisions introduced by
+merge keys. Use one explicit value per key; later entries cannot override earlier
+credential routes, limits, or rein capabilities. Errors identify the file and
+line without printing the duplicate key or value.
+
 List and validate every committed catalog profile, including its independently
 declared runtime readiness:
 

src/glas_harness/profiles.py

@@ -62,9 +62,28 @@ def _default_data_dir(kind: str) -> Path:
     return _source_root() / ("profiles" if kind == "profiles" else "registry/reins")
 
 
+class _UniqueKeyLoader(yaml.SafeLoader):
+    """Reject overwrites, including collisions introduced by YAML merges."""
+
+    def construct_mapping(self, node, deep=False):
+        mapping = super().construct_mapping(node, deep=deep)
+        seen = set()
+        for key_node, _ in node.value:
+            key = self.construct_object(key_node, deep=deep)
+            if key in seen:
+                mark = key_node.start_mark
+                # Key names and source snippets can themselves contain secrets.
+                raise yaml.YAMLError(
+                    f"duplicate YAML key at line {mark.line + 1}, "
+                    f"column {mark.column + 1}"
+                )
+            seen.add(key)
+        return mapping
+
+
 def _read_yaml(path: Path) -> dict[str, Any]:
     try:
-        data = yaml.safe_load(path.read_text())
+        data = yaml.load(path.read_text(), Loader=_UniqueKeyLoader)
     except (OSError, yaml.YAMLError) as exc:
         raise ProfileError(f"cannot read {path}: {exc}") from exc
     if not isinstance(data, dict):

tests/test_profiles.py

@@ -226,3 +226,45 @@ def test_incompatible_profile_or_rein_is_rejected(
 
     with pytest.raises(IncompatibleProfileError, match=match):
         ProfileCatalog(profiles, reins).resolve("harness.test@1.0.0")
+
+
+@pytest.mark.parametrize("kind", ["profile", "rein"])
+@pytest.mark.parametrize("nested", [False, True])
+def test_duplicate_catalog_keys_are_rejected(tmp_path, kind, nested):
+    if kind == "profile":
+        content = _profile()
+        content += ("metadata:\n  route: first\n  route: second\n" if nested
+                    else "credential_route_refs: [first]\ncredential_route_refs: [second]\n")
+    else:
+        content = _rein()
+        content = (content.replace("session_style: unattended",
+                                   "session_style: interactive\n  session_style: unattended")
+                   if nested else content + "status: disabled\n")
+    _write(tmp_path, "duplicate.yaml", content)
+    catalog = ProfileCatalog(profile_dir=tmp_path, rein_dir=tmp_path)
+    with pytest.raises(ProfileError, match="duplicate YAML key"):
+        catalog.profiles() if kind == "profile" else catalog.reins()
+
+
+def test_yaml_merge_cannot_override_catalog_values(tmp_path):
+    _write(tmp_path, "profile.yaml", _profile(extra='''metadata:
+  defaults: &defaults
+    runtime: pinned
+  selected:
+    <<: *defaults
+    runtime: different
+'''))
+    with pytest.raises(ProfileError, match="duplicate YAML key"):
+        ProfileCatalog(profile_dir=tmp_path).profiles()
+
+
+def test_nonoverlapping_yaml_merge_remains_supported(tmp_path):
+    _write(tmp_path, "profile.yaml", _profile(extra='''metadata:
+  defaults: &defaults
+    runtime: pinned
+  selected:
+    <<: *defaults
+    host: local
+'''))
+    profile = ProfileCatalog(profile_dir=tmp_path).profiles()[("harness.test", "1.0.0")]
+    assert profile.metadata["selected"] == {"runtime": "pinned", "host": "local"}

workplans/ADHOC-2026-09-06.md

@@ -52,3 +52,18 @@ the fix and passes afterwards.
 Validation: full suite 104 passed; profile catalog validation passed with
 existing readiness unchanged. Reviewed credential owner update and refreshed
 the proposed policy reference in docs/anthropic-workload-key.md.
+
+## Reject ambiguous catalog YAML
+
+```task
+id: ADHOC-2026-09-06-T03
+status: done
+priority: medium
+```
+
+Follow-up repository review found that YAML silently overwrote duplicate keys
+before profile validation. Both profile and rein descriptor loading now reject
+duplicate keys at every mapping depth, including merge collisions. Disjoint
+merges remain supported. Four regression cases reproduced silent acceptance
+before the change. Full suite: 110 passed; committed catalog validation passes.
+No residuals from this bounded fix; GLAS-WP-0012 retains the live-proof work.

workplans/GLAS-WP-0012-first-local-profile-production-proof.md

@@ -234,3 +234,18 @@ by configuration, per-lane approval and positive/negative verification.
 State Hub decisions are not a substitute for the durable authorization object.
 SECRETS-WP-0009-T03 and this plan's T02 remain waiting; runtime pinning and
 combined real proof remain required. No readiness change or real-key read.
+
+## 2026-09-06 authorization contract and policy publication
+
+Reviewed owner commits `7b4b9e3` and `083bee7` and FLEX-WP-0021. Gate-house
+GH-DEC-2026-005 resolved the contract: secrets-engine now validates the
+approval-claim and decision envelope separately and removed the incorrect
+State Hub authority requirement. Flex-auth published
+`secrets-engine.catalog-lane.lifecycle` v1; T01/T02 are done.
+
+Remaining owner gates are real decision/digest verification (FLEX-WP-0021-T03),
+consumer service deployment and handoff (T04/T05), approval-engine deployment,
+production service identity and verified lane activation. Publication is not
+deployment. T02 stays waiting, and runtime pinning and combined acceptance
+remain required. No new owner inbox message or activation evidence was found
+in this review.