重构 改为标准化输出

backend/app/cad_agent/application/outbox.py

@@ -0,0 +1,37 @@
+"""Transactional-outbox delivery orchestration.
+
+State transitions persist an outbox row in the same SQLite transaction.  This
+dispatcher is the sole path that acknowledges a row after a delivery adapter
+accepts it, which gives consumers a stable event ID for idempotent handling.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+from app.cad_agent.ports import EventPublisher, TaskRepository
+
+
+class OutboxDispatcher:
+    def __init__(self, repository: TaskRepository, publisher: EventPublisher) -> None:
+        self.repository = repository
+        self.publisher = publisher
+
+    async def dispatch_pending(self, *, limit: int = 100, task_id: str | None = None) -> list[dict[str, Any]]:
+        """Deliver pending events in order and acknowledge only on success.
+
+        A process interruption after ``publish`` but before acknowledgement is
+        deliberately delivered again.  Consumers use the stable ``event_id``
+        to collapse that at-least-once replay.
+        """
+        delivered: list[dict[str, Any]] = []
+        for item in self.repository.pending_outbox(limit, task_id=task_id):
+            event_id = item.get("event_id")
+            task_id = item.get("task_id")
+            if not isinstance(event_id, int) or not isinstance(task_id, str):
+                raise ValueError("Outbox row has no stable event identity")
+            envelope = {**item, "event_id": event_id, "task_id": task_id}
+            await self.publisher.publish(envelope)
+            self.repository.mark_outbox_published(event_id)
+            delivered.append(envelope)
+        return delivered