Update graduation workflow, promotions, and admin module improvements

database/migrations/2026_05_02_122100_drop_promotion_target_class_id_from_classes_table.php

@@ -0,0 +1,31 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        if (! Schema::hasColumn('classes', 'promotion_target_class_id')) {
+            return;
+        }
+
+        Schema::table('classes', function (Blueprint $table) {
+            $table->dropConstrainedForeignId('promotion_target_class_id');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('classes', function (Blueprint $table) {
+            $table->foreignId('promotion_target_class_id')
+                ->nullable()
+                ->after('level')
+                ->constrained('classes')
+                ->nullOnDelete()
+                ->cascadeOnUpdate();
+        });
+    }
+};