Add a dev memo-forwarding fixture and deduplicated intake notifications.

Pose, replay, and conflict stay on an injected transport with local retry
evidence. Notification receipts keep only memo id, question, class, and
submitter, and a resolve conflict stays readable.

Assistant: grok
Assistant-Session: 01a10329-31cb-78d3-b7a3-789e1fb83139

api/models/__init__.py

@@ -24,6 +24,7 @@ from api.models.contribution import Contribution, ContributionType, Contribution
 from api.models.sbom_snapshot import SBOMSnapshot
 from api.models.sbom_entry import SBOMEntry, Ecosystem
 from api.models.agent_message import AgentMessage, MessageReceipt
+from api.models.memo_notification import MemoNotificationReceipt
 from api.models.capability_catalog import CapabilityCatalog
 from api.models.capability_request import CapabilityRequest
 from api.models.tpsc import TPSCCatalog, TPSCSnapshot, TPSCEntry
@@ -77,6 +78,7 @@ __all__ = [
     "SBOMEntry", "Ecosystem",
     "AgentMessage",
     "MessageReceipt",
+    "MemoNotificationReceipt",
     "CapabilityCatalog",
     "CapabilityRequest",
     "TPSCCatalog", "TPSCSnapshot", "TPSCEntry",

api/models/memo_notification.py

@@ -0,0 +1,37 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, String, func
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column
+
+from api.models.base import Base
+
+
+class MemoNotificationReceipt(Base):
+    """Durable receipt for one informed-decision delivery id.
+
+    The delivery id is the sender's stable idempotency key. The body is only
+    memo id, question, class, and submitter. Rows are retained, not expired.
+    """
+
+    __tablename__ = "memo_notification_receipts"
+
+    delivery_id: Mapped[str] = mapped_column(String(128), primary_key=True)
+    body_digest: Mapped[str] = mapped_column(String(64), nullable=False)
+    memo_id: Mapped[str] = mapped_column(String(63), nullable=False)
+    question: Mapped[str] = mapped_column(String(400), nullable=False)
+    memo_class: Mapped[str] = mapped_column(String(63), nullable=False)
+    submitter: Mapped[str] = mapped_column(String(63), nullable=False)
+    message_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True),
+        ForeignKey("agent_messages.id", ondelete="RESTRICT"),
+        nullable=False,
+        index=True,
+    )
+    authoritative_review: Mapped[str] = mapped_column(
+        String(40), nullable=False, default="signed-in-overview"
+    )
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), nullable=False
+    )