feat(posture): add deterministic feedback proposals

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a02929-244b-7391-b933-c04010e8eedb

tools/tenancy-posture/test_validate.py

@@ -89,6 +89,41 @@ class SemanticValidationTests(unittest.TestCase):
         document["tenancy"]["review_due"] = "2026-08-16"
         self.assertIn("review_due precedes reviewed", self.validate(document)[0])
 
+    def test_evidence_freshness_must_reference_evidence_key(self) -> None:
+        document = declaration()
+        document["evidence_freshness"] = {
+            "E2": {
+                "kind": "adversarial",
+                "observed_at": "2026-08-22T22:10:25Z",
+                "valid_until": "2026-08-23T22:10:25Z",
+                "responsible_repo": "example",
+                "scope": "bounded tenant probes",
+                "remediation": "repeat the bounded run",
+            }
+        }
+        self.assertIn(
+            "evidence_freshness E2 has no evidence entry",
+            self.validate(document)[0],
+        )
+
+    def test_evidence_freshness_expiry_must_follow_observation(self) -> None:
+        document = declaration()
+        document["evidence"] = {"E2": "docs/evidence/e2.md"}
+        document["evidence_freshness"] = {
+            "E2": {
+                "kind": "adversarial",
+                "observed_at": "2026-08-22T22:10:25Z",
+                "valid_until": "2026-08-22T22:10:25Z",
+                "responsible_repo": "example",
+                "scope": "bounded tenant probes",
+                "remediation": "repeat the bounded run",
+            }
+        }
+        self.assertIn(
+            "valid_until must be after observed_at",
+            self.validate(document)[0],
+        )
+
     def test_service_names_are_unique(self) -> None:
         entry = declaration()
         document = {

tools/tenancy-posture/validate.py

@@ -67,6 +67,7 @@ def validate_semantics(document: dict[str, Any], path: pathlib.Path) -> list[str
         reason = posture.get("reason", {})
         gap = posture.get("gap", {})
         evidence = entry.get("evidence", {})
+        evidence_freshness = entry.get("evidence_freshness", {})
 
         reviewed = dt.date.fromisoformat(posture["reviewed"])
         review_due = dt.date.fromisoformat(posture["review_due"])
@@ -92,6 +93,22 @@ def validate_semantics(document: dict[str, Any], path: pathlib.Path) -> list[str
                     f"{name}: implemented {axis}{level} must be above current {axis}{current_level}"
                 )
 
+        for key, freshness in evidence_freshness.items():
+            if key not in evidence:
+                errors.append(f"{name}: evidence_freshness {key} has no evidence entry")
+            observed_at = dt.datetime.fromisoformat(
+                freshness["observed_at"].replace("Z", "+00:00")
+            )
+            valid_until_raw = freshness.get("valid_until")
+            if valid_until_raw:
+                valid_until = dt.datetime.fromisoformat(
+                    valid_until_raw.replace("Z", "+00:00")
+                )
+                if valid_until <= observed_at:
+                    errors.append(
+                        f"{name}: evidence_freshness {key} valid_until must be after observed_at"
+                    )
+
         provider = entry.get("provider", {})
         for axis, reach in provider.get("axes", {}).items():
             available = reach["available"]