Add initial Todo items and CalDAV sync

app/Models/TodoType.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class TodoType extends Model
+{
+    use HasFactory;
+
+    protected $fillable = ['name'];
+
+    public $timestamps = false;
+
+    public function todos()
+    {
+        return $this->hasMany(Todo::class, 'type_id');
+    }
+}