docs(P10): complete contract-ingestor-identity-validation phase (v1.13.13)

---ci---
project: acdl
phase: 10
milestone: v1.14
status: complete
requirements:
  covered: [REQ-144]
  partial: []
---/ci---

tests/test_contract_ingestor.py

@@ -500,4 +500,43 @@ class TestValidateChangeRequest:
         resp = ingestor.lambda_handler(event, None)
         assert resp["statusCode"] == 200
         body = json.loads(resp["body"])
-        assert body["action"] == "validate_change_request"
+        assert body["action"] == "validate_change_request"
+
+
+class TestV14IdentityValidation:
+    """v1.14 (REQ-144): contractId format, environment enum, error length
+    validation + spoofing resistance."""
+
+    def test_invalid_contract_id_rejected(self, moto_contracts_table, sample_payload):
+        sample_payload["contractId"] = "bad contract!@#"
+        event = {"body": json.dumps(sample_payload), "requestContext": {}}
+        resp = ingestor.lambda_handler(event, None)
+        assert resp["statusCode"] == 400
+        assert "invalid contractId" in resp["body"]
+
+    def test_contract_id_too_long_rejected(self, moto_contracts_table, sample_payload):
+        sample_payload["contractId"] = "a" * 65
+        event = {"body": json.dumps(sample_payload), "requestContext": {}}
+        resp = ingestor.lambda_handler(event, None)
+        assert resp["statusCode"] == 400
+        assert "invalid contractId" in resp["body"]
+
+    def test_invalid_environment_rejected(self, moto_contracts_table, sample_payload):
+        sample_payload["environment"] = "staging"
+        event = {"body": json.dumps(sample_payload), "requestContext": {}}
+        resp = ingestor.lambda_handler(event, None)
+        assert resp["statusCode"] == 400
+        assert "invalid environment" in resp["body"]
+
+    def test_valid_environments_accepted(self, moto_contracts_table, sample_payload):
+        for env in ["dev", "qa", "prod", "dr"]:
+            sample_payload["environment"] = env
+            event = {"body": json.dumps(sample_payload), "requestContext": {}}
+            resp = ingestor.lambda_handler(event, None)
+            assert resp["statusCode"] == 200
+
+    def test_abac_reliance_documented(self):
+        """The _validate_caller_identity docstring documents the ABAC reliance."""
+        docstring = ingestor._validate_caller_identity.__doc__
+        assert "ABAC" in docstring
+        assert "PrincipalTag" in docstring