add Comment persistence: model, migration, eloquent + fake repo

backend/app/Comment/CommentModel.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Comment;
+
+use DateTimeImmutable;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Model;
+
+/**
+ * @property int $id
+ * @property int $post_id
+ * @property int $user_id
+ * @property string $body
+ * @property DateTimeImmutable $created_at
+ *
+ * @method static Builder<static>|CommentModel newModelQuery()
+ * @method static Builder<static>|CommentModel newQuery()
+ * @method static Builder<static>|CommentModel query()
+ * @method static Builder<static>|CommentModel whereId($value)
+ * @method static Builder<static>|CommentModel wherePostId($value)
+ * @method static Builder<static>|CommentModel whereUserId($value)
+ * @method static Builder<static>|CommentModel whereBody($value)
+ * @method static Builder<static>|CommentModel whereCreatedAt($value)
+ *
+ * @mixin \Eloquent
+ */
+class CommentModel extends Model
+{
+    protected $table = 'comments';
+
+    public $timestamps = false;
+
+    protected $fillable = [
+        'post_id',
+        'user_id',
+        'body',
+        'created_at',
+    ];
+
+    protected $casts = [
+        'created_at' => 'immutable_datetime',
+    ];
+}