Bug: Accounting System Stock Reconciliation Failure

**Describe the bug**
The Exine school supplies store accounting system fails to properly reconcile inventory during the periodic stock audit process. Sales transactions are being recorded but arriving shipments (arrivages) are not being correctly matched against the inventory database, causing discrepancies between physical counts and system records.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to 'Inventory Management' section
2. Record incoming shipment of 100 units of product
3. Process sales transactions (e.g., 25 units sold)
4. Run 'Reconciliation Report'
5. See error - inventory total shows incorrect quantity

**Expected behavior**
The system should accurately:
- Track incoming shipments (stock arrivals)
- Deduct sold quantities from inventory
- Show correct inventory balance in reconciliation reports
- Maintain complete historical records of all movements

**Screenshots**
[Add screenshots of incorrect inventory counts and reconciliation errors if applicable]

**Desktop (please complete the following information):**
- OS: [e.g. Windows 10, Linux]
- Browser: [e.g. Chrome, Firefox]
- Version: [e.g. 1.0.0]

**Smartphone (please complete the following information):**
- Device: [e.g. iPhone12]
- OS: [e.g. iOS14]
- Browser: [e.g. Safari]
- Version: [e.g. 1.0.0]

**Additional context**
- Store location: Algeria
- Product category: School supplies (Exine brand)
- Issue severity: High - affects financial and inventory accuracy
- Frequency: Occurs consistently during end-of-period reconciliation