Complete publish preview Phase 2A with retention, refresh and cache consistency

backend/app/repositories/scheme_artifacts.py

@@ -1,6 +1,6 @@
 from uuid import uuid4
 
-from sqlalchemy import asc, desc, select
+from sqlalchemy import asc, delete, desc, select
 
 from app.db.session import AsyncSessionLocal
 from app.models.scheme_artifact import SchemeArtifactRecord
@@ -99,3 +99,16 @@ async def get_latest_scheme_artifact(
 
         result = await session.execute(stmt)
         return result.scalar_one_or_none()
+
+
+async def delete_scheme_artifacts_by_artifact_ids(artifact_ids: list[str]) -> int:
+    if not artifact_ids:
+        return 0
+
+    async with AsyncSessionLocal() as session:
+        stmt = delete(SchemeArtifactRecord).where(
+            SchemeArtifactRecord.artifact_id.in_(artifact_ids)
+        )
+        result = await session.execute(stmt)
+        await session.commit()
+        return int(result.rowcount or 0)