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+# Domain Model
+
+## Core entities
+
+- ItemTemplate: reusable defaults for common purchase types
+- Item: individual acquired object being tracked for resale
+- PriceEstimate: a resale suggestion from comps or manual input
+- ItemNote: internal notes and condition updates
+- ItemPhoto: images attached to the item
+
+## Item lifecycle
+
+1. Created from a template or from scratch
+2. Marked in stock
+3. Optionally listed
+4. Sold or removed from inventory
+
+## Tracking rules
+
+- The creator of the item is stored on the record and shown in item views
+- Profit is based on sold price minus purchase price, fees, and shipping cost
+- Estimated resale price is only a suggestion until sold data exists