backend: align API/models with current PostgreSQL schema

app/Models/VenueImage.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+
+class VenueImage extends Model
+{
+    use HasFactory;
+
+    public $timestamps = false;
+
+    protected $table = 'venue_images';
+
+    protected $fillable = [
+        'venue_id',
+        'url',
+        'sort_order',
+    ];
+}