Add inventory domain foundation

backend/app/inventory/__init__.py

@@ -0,0 +1,33 @@
+"""Inventory domain models, persistence, and business services."""
+
+from app.inventory.exceptions import (
+    DuplicateAssetID,
+    InventoryError,
+    InventoryValidationError,
+    MinerNotFound,
+)
+from app.inventory.models import (
+    InventoryCreateRequest,
+    InventoryMinerDetail,
+    InventoryMinerSummary,
+    InventorySearchFilters,
+    InventoryTag,
+    InventoryUpdateRequest,
+)
+from app.inventory.repository import InventoryRepository
+from app.inventory.service import InventoryService
+
+__all__ = [
+    "DuplicateAssetID",
+    "InventoryCreateRequest",
+    "InventoryError",
+    "InventoryMinerDetail",
+    "InventoryMinerSummary",
+    "InventoryRepository",
+    "InventorySearchFilters",
+    "InventoryService",
+    "InventoryTag",
+    "InventoryUpdateRequest",
+    "InventoryValidationError",
+    "MinerNotFound",
+]