feat(bom): canonical lot mappings and updated vendor spec docs

internal/localdb/models.go

@@ -283,6 +283,21 @@ type VendorSpecItem struct {
 	ResolvedLotName     string   `json:"resolved_lot_name,omitempty"`
 	ResolutionSource    string   `json:"resolution_source,omitempty"` // "book", "manual", "unresolved"
 	ManualLotSuggestion string   `json:"manual_lot_suggestion,omitempty"`
+	LotQtyPerPN         int      `json:"lot_qty_per_pn,omitempty"`
+	LotAllocations      []VendorSpecLotAllocation `json:"lot_allocations,omitempty"`
+	LotMappings         []VendorSpecLotMapping `json:"lot_mappings,omitempty"`
+}
+
+type VendorSpecLotAllocation struct {
+	LotName  string `json:"lot_name"`
+	Quantity int    `json:"quantity"` // quantity of LOT per 1 vendor PN
+}
+
+// VendorSpecLotMapping is the canonical persisted LOT mapping for a vendor PN row.
+// It stores all mapped LOTs (base + bundle) uniformly.
+type VendorSpecLotMapping struct {
+	LotName       string `json:"lot_name"`
+	QuantityPerPN int    `json:"quantity_per_pn"`
 }
 
 // VendorSpec is a JSON-encodable slice of VendorSpecItem