feat: add searches table, model, and factory for API search logging

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/Models/Search.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Models;
+
+use Database\Factories\SearchFactory;
+use Illuminate\Database\Eloquent\Attributes\Fillable;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+#[Fillable(['lat_bucket', 'lng_bucket', 'fuel_type', 'results_count', 'lowest_pence', 'highest_pence', 'avg_pence', 'searched_at', 'ip_hash'])]
+class Search extends Model
+{
+    /** @use HasFactory<SearchFactory> */
+    use HasFactory;
+
+    public $timestamps = false;
+
+    protected function casts(): array
+    {
+        return [
+            'searched_at' => 'datetime',
+        ];
+    }
+}