Implemented the authenticated admin contact system.

app/Models/SupportMessage.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace App\Models;
+
+use Database\Factories\SupportMessageFactory;
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+#[Fillable(['support_conversation_id', 'user_id', 'body'])]
+class SupportMessage extends Model
+{
+    /** @use HasFactory<SupportMessageFactory> */
+    use HasFactory;
+
+    public function conversation(): BelongsTo
+    {
+        return $this->belongsTo(SupportConversation::class, 'support_conversation_id');
+    }
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function attachments(): HasMany
+    {
+        return $this->hasMany(SupportAttachment::class);
+    }
+}