fix: Graph fetch relations with sales & purchases models.

feat: Inventory tracker algorithm lots with FIFO or LIFO cost method.

server/src/models/SaleEstimate.js

@@ -23,8 +23,18 @@ export default class SaleEstimate extends mixin(TenantModel, [CachableModel]) {
    */
   static get relationMappings() {
     const ItemEntry = require('@/models/ItemEntry');
+    const Customer = require('@/models/Customer');
 
     return {
+      customer: {
+        relation: Model.BelongsToOneRelation,
+        modelClass: this.relationBindKnex(Customer.default),
+        join: {
+          from: 'sales_estimates.customerId',
+          to: 'customers.id',
+        },
+      },
+
       entries: {
         relation: Model.HasManyRelation,
         modelClass: this.relationBindKnex(ItemEntry.default),
@@ -32,6 +42,9 @@ export default class SaleEstimate extends mixin(TenantModel, [CachableModel]) {
           from: 'sales_estimates.id',
           to: 'items_entries.referenceId',
         },
+        filter(builder) {
+          builder.where('reference_type', 'SaleEstimate');
+        },
       },
     };
   }