Import/calculations improvements

inventory-server/scripts/import/stock-snapshots.js

@@ -151,7 +151,10 @@ async function importStockSnapshots(prodConnection, localConnection, incremental
 
         recordsAdded += batch.length;
       } catch (err) {
+        // Fail the step: the next incremental starts at MAX(snapshot_date), so a
+        // swallowed batch error would leave a permanent hole that is never revisited.
         console.error(`Error inserting batch at offset ${i} (date range ending ${currentDate}):`, err.message);
+        throw err;
       }
     }
 
@@ -165,7 +168,7 @@ async function importStockSnapshots(prodConnection, localConnection, incremental
       current: processedRows,
       total: totalRows,
       elapsed: formatElapsedTime(startTime),
-      rate: calculateRate(processedRows, startTime)
+      rate: calculateRate(startTime, processedRows)
     });
   }