Switch from timestamp to datetime for maintenance completed_at

database/migrations/2026_07_21_000002_change_maintenance_completed_at_to_datetime.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
+{
+    /**
+     * completed_at was added in 2026_05_18_094309 as a TIMESTAMP. The
+     * 2026_07_17_000001 migration moved start_date and completion_date
+     * (now expected_completion_date) to DATETIME for consistency and to
+     * dodge TIMESTAMP's 2038 range limit + session-timezone auto-
+     * conversion, but skipped completed_at. This finishes that job.
+     *
+     * Values fit in both types, so no data transformation is required.
+     */
+    public function up(): void
+    {
+        Schema::table('maintenances', function (Blueprint $table) {
+            $table->dateTime('completed_at')->nullable()->change();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('maintenances', function (Blueprint $table) {
+            $table->timestamp('completed_at')->nullable()->change();
+        });
+    }
+};