chg: [alignment] Added validation rule to avoid duplicates

src/Model/Table/AlignmentsTable.php

@@ -4,6 +4,7 @@ namespace App\Model\Table;
 
 use App\Model\Table\AppTable;
 use Cake\ORM\Table;
+use Cake\ORM\RulesChecker;
 use Cake\Validation\Validator;
 
 class AlignmentsTable extends AppTable
@@ -26,6 +27,15 @@ class AlignmentsTable extends AppTable
         return $validator;
     }
 
+    public function buildRules(RulesChecker $rules): RulesChecker
+    {
+        $rules->add($rules->isUnique(
+            ['individual_id', 'organisation_id', 'type'],
+            __('This alignment already exists.')
+        ));
+        return $rules;
+    }
+
     public function setAlignment($organisation_id, $individual_id, $type): void
     {
         $query = $this->find();