✨ What's new:

• Every inventory item can now have a quality value (0–1000)
• Quality is displayed as a colored grade badge:
  Worthless · Useable · Base · Good · Best
• Set quality using an exact number or pick a grade from the dropdown
• Filter your inventory by quality grade — including an "Ungraded" option for legacy items
• CSV import now supports a quality column — accepts both numbers (675) and grade names (Good)
• CSV export & Google Sheets sync include quality automatically

🛠️ How to use:

When adding or editing an item, you'll see a new Quality section with:

• a number input (0–1000)
• a grade dropdown

Picking a grade sets a default value you can refine.
The grade badge shows up on all item cards in your inventory list.

Note:
Quality is fully optional — existing items without quality remain unchanged.