Google Sheets Garment Stock Tracker

I need a single Google Sheet that lets my team record everything happening to our garments while keeping all formulas and structure locked down.
• Current Stock section – laid out with columns for Item Name, Category, Quantity Available and Stock Location. This area should update automatically as new entries come in.
• Transaction log – one place where the data-entry staff will add what was pressed, dispatched, moved to the godown or returned. Because I want the day-to-day activity organised by item, each row should start with the garment’s SKU or description, followed by a drop-down to choose the transaction type, the quantity and the date. From there your formulas will feed the Current Stock section.
I also need:
• Built-in checks that stop negative stock.
• Cell and sheet protection so users can add rows but cannot touch hidden formula columns or break references.
• Simple filters or a pivot view so I can instantly see balances by category or location.

Hand-over deliverables
1. The live Google Sheet, fully protected and ready for use.
2. A brief note or Loom video showing where staff should enter data and how the automatic balances work.