Feature: Add ACS courier integration

ACS rate driver (live price quotes via ACS_Price_Calculation, cached postcode-to-station lookups) and fulfillment service (voucher creation, label printing, end-of-day pickup manifest). Adds a per-rate pricing_mode column so admins can choose live API pricing vs. a fixed price on ACS-driven shipping rates, surfaced via a custom Rates page.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/Shipping/Carriers/Acs/Jobs/WarmAcsAreaCacheJob.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Modules\Core\Shipping\Carriers\Acs\Jobs;
+
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Foundation\Bus\Dispatchable;
+use Illuminate\Queue\InteractsWithQueue;
+use Illuminate\Queue\SerializesModels;
+use Modules\Core\Shipping\Carriers\Acs\AreaResolver;
+
+class WarmAcsAreaCacheJob implements ShouldQueue
+{
+    use Dispatchable;
+    use InteractsWithQueue;
+    use Queueable;
+    use SerializesModels;
+
+    public int $tries = 3;
+
+    public int $backoff = 60;
+
+    public function handle(AreaResolver $areaResolver): void
+    {
+        $areaResolver->warmAll();
+    }
+}