feat: add GET /api/stations nearby stations endpoint with haversine query and search logging

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

app/Http/Requests/Api/NearbyStationsRequest.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace App\Http\Requests\Api;
+
+use App\Enums\FuelType;
+use Illuminate\Foundation\Http\FormRequest;
+
+class NearbyStationsRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'lat' => ['required', 'numeric', 'between:-90,90'],
+            'lng' => ['required', 'numeric', 'between:-180,180'],
+            'fuel_type' => ['required', 'string'],
+            'radius' => ['nullable', 'numeric', 'between:0.1,50'],
+            'sort' => ['nullable', 'string', 'in:price,distance'],
+            'pricing_mode' => ['nullable', 'string', 'in:pump'],
+        ];
+    }
+
+    public function fuelType(): FuelType
+    {
+        return FuelType::fromAlias($this->string('fuel_type')->toString());
+    }
+
+    public function radius(): float
+    {
+        return (float) $this->input('radius', 10.0);
+    }
+
+    public function sort(): string
+    {
+        return $this->input('sort', 'price');
+    }
+}