feat: add miner detail view

backend/app/inventory/service.py

@@ -137,6 +137,13 @@ class InventoryService:
             raise MinerNotFound(miner_id)
         return self._detail_model(row)
 
+    def get_current_miner(self, miner_id: UUID) -> InventoryMinerDetail:
+        """Return current Inventory identity and the latest observation."""
+        row = self.repository.get_current_miner_by_id(miner_id)
+        if not row:
+            raise MinerNotFound(miner_id)
+        return self._detail_model(row)
+
     def get_asset_id_history(
         self,
         miner_id: UUID,