feat: decide the staffing split per ski level

migrations/Version20261105100000.php

@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Replaces the staffing matrix's split flag with one flag per ski level.
+ *
+ * A split row takes over every level it has, so it keeps planning the same assignments. The way
+ * back folds the two flags into one, which loses a row that takes over one level of two.
+ *
+ * Written by hand rather than taken from doctrine:migrations:diff, which also carries the
+ * pre-existing drift of the dev database.
+ */
+final class Version20261105100000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Replace staffing_rule.split with split_beginner / split_advanced';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE staffing_rule ADD split_beginner TINYINT NOT NULL, ADD split_advanced TINYINT NOT NULL');
+        $this->addSql('UPDATE staffing_rule SET split_beginner = split AND ski_beginner, split_advanced = split AND ski_advanced');
+        $this->addSql('ALTER TABLE staffing_rule DROP split');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE staffing_rule ADD split TINYINT NOT NULL');
+        $this->addSql('UPDATE staffing_rule SET split = split_beginner OR split_advanced');
+        $this->addSql('ALTER TABLE staffing_rule DROP split_beginner, DROP split_advanced');
+    }
+}