Comments: Added back-end content reference handling

Also added archived property, to be added.

database/migrations/2025_04_18_215145_add_content_refs_and_archived_to_comments.php

@@ -0,0 +1,30 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('comments', function (Blueprint $table) {
+            $table->string('content_ref');
+            $table->boolean('archived')->index();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('comments', function (Blueprint $table) {
+            $table->dropColumn('content_ref');
+            $table->dropColumn('archived');
+        });
+    }
+};