test: add expected refusal receipt fixture

Author: LalaSkye

docs/enterprise-shaped-scenarios/expected_refusal_receipt.json

@@ -0,0 +1,17 @@
+{
+  "receipt_id": "RCP-ESP-001-EXPECTED",
+  "scenario_id": "ESP-001",
+  "attempt_id": "ATT-ESP-001-INVALID-001",
+  "attempted_action": "SEND_EXTERNAL_EMAIL",
+  "actor": "agent://morpheus-draft-bot-v1",
+  "action_type": "SEND_EXTERNAL_EMAIL",
+  "recipient_scope": "external:partner-domain.com",
+  "payload_hash": "sha256:a3f8c2d1e7b904561ac38fd2e190bba47c2d3f8a1e056b7c9d4e2f1a8b3c7d90",
+  "missing_field": "authority_token",
+  "decision": "DENY",
+  "refusal_reason": "authority_token absent — no valid DecisionRecord for this actor, action_type, recipient_scope, and payload at gate time",
+  "downstream_send": false,
+  "receipt_written": true,
+  "state_mutated": false,
+  "replay_marker": "same invalid attempt must produce same decision and missing_field"
+}