feat: add postcode resolution to /api/stations and Filament SearchResource

Extends NearbyStationsRequest to accept `postcode` (full or outcode) as an alternative to lat/lng. PostcodeService resolves it via postcodes.io and falls through to coordinates. Also adds SearchResource to the Filament admin panel for viewing logged search activity with fuel type filter and price/distance stats columns. Includes SQLite GREATEST/LEAST function polyfills in AppServiceProvider for test compatibility.

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

app/Http/Controllers/Api/AuthController.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace App\Http\Controllers\Api;
+
+use App\Http\Controllers\Controller;
+use App\Models\User;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\Auth;
+use Illuminate\Validation\Rules\Password;
+use Laravel\Sanctum\PersonalAccessToken;
+
+class AuthController extends Controller
+{
+    public function register(Request $request): JsonResponse
+    {
+        $data = $request->validate([
+            'name' => ['required', 'string', 'max:255'],
+            'email' => ['required', 'email', 'max:255', 'unique:users,email'],
+            'password' => ['required', 'confirmed', Password::defaults()],
+        ]);
+
+        $user = User::create($data);
+        $token = $user->createToken('api')->plainTextToken;
+
+        return response()->json(['token' => $token, 'user' => $user], 201);
+    }
+
+    public function login(Request $request): JsonResponse
+    {
+        $credentials = $request->validate([
+            'email' => ['required', 'email'],
+            'password' => ['required', 'string'],
+        ]);
+
+        if (! Auth::attempt($credentials)) {
+            return response()->json(['message' => 'Invalid credentials.'], 401);
+        }
+
+        /** @var User $user */
+        $user = Auth::user();
+        $token = $user->createToken('api')->plainTextToken;
+
+        return response()->json(['token' => $token, 'user' => $user]);
+    }
+
+    public function logout(Request $request): JsonResponse
+    {
+        /** @var PersonalAccessToken $token */
+        $token = $request->user()->currentAccessToken();
+        $token->delete();
+
+        return response()->json(['message' => 'Logged out.']);
+    }
+
+    public function me(Request $request): JsonResponse
+    {
+        return response()->json($request->user());
+    }
+}