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

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

database/factories/SearchFactory.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\Search;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<Search> */
+class SearchFactory extends Factory
+{
+    public function definition(): array
+    {
+        $lowest = fake()->numberBetween(12000, 15000);
+        $highest = $lowest + fake()->numberBetween(100, 3000);
+
+        return [
+            'lat_bucket' => round(fake()->latitude(49.9, 60.9), 2),
+            'lng_bucket' => round(fake()->longitude(-8.2, 1.8), 2),
+            'fuel_type' => fake()->randomElement(['b7_standard', 'e10', 'e5']),
+            'results_count' => fake()->numberBetween(5, 100),
+            'lowest_pence' => $lowest,
+            'highest_pence' => $highest,
+            'avg_pence' => round(($lowest + $highest) / 2, 2),
+            'searched_at' => now(),
+            'ip_hash' => hash('sha256', fake()->ipv4()),
+        ];
+    }
+}