Incorrect Harvest Yield Calculation

[rmsonge]

The "Harvest Report" undercounts yields when batch harvesting (e.g., entering 50kg for 5 rows calculates as 5kg total).

Steps to Reproduce:

1. Plant 10 rows of lettuce.
2. Record harvest:
   • Quantity: 20kg
   • Rows harvested: 2
3. Check report → shows 4kg instead of 20kg.

Expected Behavior:
Yield = (Quantity) × (Rows Harvested / Total Rows).

Actual Behavior:
Yield = (Quantity) / (Rows Harvested).