Minor fixes

app/Models/Currency.php

@@ -47,4 +47,21 @@ class Currency extends Model
     {
         return $this->hasMany(RecurringInvoice::class);
     }
+
+    public function checkTransactions()
+    {
+        if (
+            $this->customers()->exists() ||
+            $this->items()->exists() ||
+            $this->invoices()->exists() ||
+            $this->estimates()->exists() ||
+            $this->expenses()->exists() ||
+            $this->payments()->exists() ||
+            $this->recurringInvoices()->exists()
+        ) {
+            return true;
+        }
+
+        return false;
+    }
 }

app/Models/Invoice.php

@@ -27,7 +27,6 @@ class Invoice extends Model implements HasMedia
 
     public const STATUS_DRAFT = 'DRAFT';
     public const STATUS_SENT = 'SENT';
-    public const STATUS_OVERDUE = 'OVERDUE';
     public const STATUS_VIEWED = 'VIEWED';
     public const STATUS_COMPLETED = 'COMPLETED';