feat: UserDeadline Functionality

app/Models/UserDeadline.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class UserDeadline extends Model
+{
+    use HasFactory;
+
+    protected $fillable = [
+        'user_id',
+        'deadline_id',
+        'completed_at',
+    ];
+
+    public function user()
+    {
+        return $this->belongsTo(User::class);
+    }
+    public function deadline()
+    {
+        return $this->belongsTo(Deadline::class);
+    }
+}