chore: update document approval workflow and bug fixes

Modules/DocumentManagement/app/Models/DocumentApproval.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace Modules\DocumentManagement\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+// use Modules\DocumentManagement\Database\Factories\DocumentApprovalFactory;
+
+class DocumentApproval extends Model
+{
+    use HasFactory;
+
+    /**
+     * The attributes that are mass assignable.
+     */
+    protected $fillable = [
+        'document_id',
+        'approved_by',
+        'status',
+        'comments',
+        'approved_at',
+    ];
+
+    protected $casts = [
+        'approved_at' => 'datetime',
+    ];
+
+    public function document()
+    {
+        return $this->belongsTo(Document::class);
+    }
+
+    public function approver()
+    {
+        return $this->belongsTo(\App\Models\User::class, 'approved_by');
+    }
+}