Implement FastAPI Temporal MVP pipeline

app/domain/models/asset.py

@@ -0,0 +1,21 @@
+"""Domain asset model."""
+
+from dataclasses import dataclass
+from datetime import datetime
+from typing import Any
+
+from app.domain.enums import AssetType, WorkflowStepName
+
+
+@dataclass(slots=True)
+class Asset:
+    """Business representation of a generated asset."""
+
+    id: int
+    order_id: int
+    asset_type: AssetType
+    step_name: WorkflowStepName | None
+    uri: str
+    metadata_json: dict[str, Any] | None
+    created_at: datetime
+