feat: harden campaign delivery and editing

tests/test_postbox_integration.py

@@ -1,11 +1,13 @@
 from __future__ import annotations
 
 import unittest
+from datetime import UTC, datetime
 
 from govoplan_core.core.postbox import (
     PostboxDeliveryCatalogRef,
     PostboxDirectoryEntryRef,
     PostboxDeliveryRequest,
+    PostboxDeliveryReceiptSummaryRef,
     PostboxDeliveryResult,
     PostboxTargetRef,
 )
@@ -55,11 +57,39 @@ class _PostboxDelivery:
             classification="internal",
         )
 
+    def link_evidence(self, session, *, tenant_id, message_id, attachment):
+        del session, tenant_id, message_id, attachment
+        return None
+
+    def delivery_receipt_summaries(
+        self,
+        session,
+        *,
+        tenant_id,
+        producer_module,
+        delivery_ids,
+    ):
+        del session
+        assert tenant_id == "tenant-1"
+        assert producer_module == "campaigns"
+        return {
+            delivery_id: PostboxDeliveryReceiptSummaryRef(
+                delivery_id=delivery_id,
+                message_id="message-1",
+                postbox_id="postbox-1",
+                delivery_status="accepted",
+                accepted_at=datetime(2026, 7, 30, tzinfo=UTC),
+                currently_readable=True,
+                read_receipt_count=1,
+            )
+            for delivery_id in delivery_ids
+        }
+
 
 class PostboxCampaignIntegrationTests(unittest.TestCase):
     def test_optional_delivery_boundary_is_typed_and_explicit(self) -> None:
         delegate = _PostboxDelivery()
-        integration = PostboxCampaignIntegration(delegate, delegate)
+        integration = PostboxCampaignIntegration(delegate, delegate, delegate)
         request = PostboxDeliveryRequest(
             tenant_id="tenant-1",
             target=PostboxTargetRef(postbox_id="postbox-1"),
@@ -73,8 +103,15 @@ class PostboxCampaignIntegrationTests(unittest.TestCase):
         result = integration.deliver(object(), request)
 
         self.assertTrue(integration.available)
+        self.assertTrue(integration.receipt_evidence_available)
         self.assertEqual("delivery-1", result.delivery_id)
         self.assertEqual(request, delegate.requests[0][1])
+        summaries = integration.delivery_receipt_summaries(
+            object(),
+            tenant_id="tenant-1",
+            delivery_ids=["delivery-1"],
+        )
+        self.assertEqual(1, summaries["delivery-1"].read_receipt_count)
 
     def test_missing_postbox_is_reported_without_importing_module_code(
         self,
@@ -91,6 +128,15 @@ class PostboxCampaignIntegrationTests(unittest.TestCase):
         )
 
         self.assertFalse(integration.available)
+        self.assertFalse(integration.receipt_evidence_available)
+        self.assertEqual(
+            {},
+            integration.delivery_receipt_summaries(
+                object(),
+                tenant_id="tenant-1",
+                delivery_ids=["delivery-1"],
+            ),
+        )
         with self.assertRaises(PostboxDeliveryUnavailable):
             integration.deliver(object(), request)