++ fix: add pdf download visibility setting

database/migrations/2026_04_16_000001_add_pdf_download_visible_to_settings_table.php

@@ -0,0 +1,22 @@
+<?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
+    {
+        Schema::table('settings', function (Blueprint $table) {
+            $table->boolean('pdf_viewer_show_download')->default(true)->after('assignment_link_ttl_hours');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('settings', function (Blueprint $table) {
+            $table->dropColumn('pdf_viewer_show_download');
+        });
+    }
+};