fix: correctly apply due dates for contract and invoice upload reminders

src/Model/TimelineFilterDto.php

@@ -2,12 +2,12 @@
 
 namespace App\Model;
 
-use Carbon\CarbonPeriod;
+use Carbon\CarbonPeriodImmutable;
 
 class TimelineFilterDto extends AssignmentFilterDto
 {
     protected bool $includePast = true;
-    protected ?CarbonPeriod $_period = null;
+    protected ?CarbonPeriodImmutable $_period = null;
 
     public function getDateFrom(): ?\DateTimeImmutable
     {
@@ -27,12 +27,12 @@ class TimelineFilterDto extends AssignmentFilterDto
         return $this->dateTo;
     }
 
-    public function getPeriod(): ?CarbonPeriod
+    public function getPeriod(): ?CarbonPeriodImmutable
     {
         return $this->_period;
     }
 
-    public function setPeriod(?CarbonPeriod $_period): static
+    public function setPeriod(?CarbonPeriodImmutable $_period): static
     {
         $this->_period = $_period;