feat: strengthen transactional audit delivery

src/govoplan_audit/backend/outbox.py

@@ -21,6 +21,7 @@ from govoplan_core.core.events import (
     ensure_event_trace,
     publish_platform_event,
 )
+from govoplan_core.core.institutional import GovernedContextEnvelope
 
 EventDispatcher = Callable[[PlatformEvent], None]
 
@@ -562,6 +563,19 @@ def _event_from_payload(payload: Mapping[str, Any]) -> PlatformEvent:
         subject=_object_ref(payload.get("subject")),
         resource=_object_ref(payload.get("resource")),
         classification=cast(EventClassification, str(payload.get("classification") or "internal")),
+        institutional_context=_institutional_context(
+            payload.get("institutional_context")
+        ),
+    )
+
+
+def _institutional_context(
+    value: object,
+) -> GovernedContextEnvelope | None:
+    return (
+        GovernedContextEnvelope.from_mapping(value)
+        if isinstance(value, Mapping)
+        else None
     )