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.

config/shippingCarriers/acs.php

@@ -0,0 +1,50 @@
+<?php
+
+/*
+|--------------------------------------------------------------------------
+| ACS Courier credentials
+|--------------------------------------------------------------------------
+|
+| ACS requires two credential mechanisms simultaneously: an AcsApiKey
+| HTTP header (gates the REST gateway itself) and four account fields
+| (Company_ID/Company_Password/User_ID/User_Password) sent in every
+| request body. Both are supplied by ACS when your account is set up.
+|
+| Set these via environment variables — never commit real values.
+|
+| ACS_BASE_URL           Root REST endpoint (unversioned, single URL for
+|                        every ACSAlias call).
+| ACS_API_KEY            The AcsApiKey header value.
+| ACS_COMPANY_ID         Company_ID body field.
+| ACS_COMPANY_PASSWORD   Company_Password body field.
+| ACS_USER_ID            User_ID body field.
+| ACS_USER_PASSWORD      User_Password body field.
+| ACS_BILLING_CODE       Your ACS credit/billing code, used for price
+|                        calculation and voucher creation.
+| ACS_SENDER_*           Static sender details reused on every voucher.
+|
+*/
+
+return [
+
+    'base_url' => env('ACS_BASE_URL', 'https://webservices.acscourier.net/ACSRestServices/api/ACSAutoRest'),
+
+    'api_key' => env('ACS_API_KEY'),
+
+    'company_id' => env('ACS_COMPANY_ID'),
+    'company_password' => env('ACS_COMPANY_PASSWORD'),
+    'user_id' => env('ACS_USER_ID'),
+    'user_password' => env('ACS_USER_PASSWORD'),
+
+    'billing_code' => env('ACS_BILLING_CODE'),
+
+    'sender' => [
+        'name' => env('ACS_SENDER_NAME'),
+        'address' => env('ACS_SENDER_ADDRESS'),
+        'zip_code' => env('ACS_SENDER_ZIP'),
+        'phone' => env('ACS_SENDER_PHONE'),
+    ],
+
+    'timeout' => env('ACS_HTTP_TIMEOUT', 10),
+
+];