DHL: Auslandslabels mit V53WPAK, Feldlaengen und Tracking-Wiederholung

Log-Analyse 26.08. (P0-2, P1-5, P2-3):
- Produktcode fuer DHL Paket International ist V53WPAK; mit V53PAK wurde
  kein einziges Auslandslabel erzeugt. Alte Codes werden gemappt
  (LEGACY_PRODUCT_CODE_ALIASES), Abrechnungsnummer und Masse suchen auch
  unter den alten Setting-Schluesseln (dhl_account_v53pak) und Env-Namen.
- Zu lange Felder (Name, Stadt, Telefon, Referenz) werden auf die
  DHL-Grenzen gekuerzt bzw. bereinigt statt den Versand abzulehnen; refNo
  mindestens 8 Zeichen, sonst die Bestellreferenz.
- Tracking wiederholt bei HTTP 5xx der Unified-API bis zu dreimal.

Zolldaten fuer die Schweiz (P0-3) sind nicht Teil dieses Commits.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tests/Unit/Dhl/DhlTrackingServerErrorRetryTest.php

@@ -0,0 +1,60 @@
+<?php
+
+use App\Http\Controllers\SettingController;
+use App\Services\DhlTrackingService;
+use Illuminate\Support\Facades\Http;
+
+beforeEach(function () {
+    $reflection = new ReflectionClass(SettingController::class);
+    $property = $reflection->getProperty('cachedDhlConfig');
+    $property->setAccessible(true);
+    $property->setValue(null, [
+        'api_key' => 'cached-test-api-key-1234',
+    ]);
+});
+
+afterEach(function () {
+    SettingController::flushDhlConfigCache();
+    DhlTrackingService::clearQuotaPause();
+});
+
+it('retries a transient server error and returns the successful response', function () {
+    Http::fakeSequence()
+        ->push(['title' => 'Internal Server Error'], 500)
+        ->push(['shipments' => [[
+            'id' => '00340434292135100148',
+            'status' => ['statusCode' => 'delivered', 'description' => 'Zugestellt'],
+        ]]], 200);
+
+    $result = (new DhlTrackingService)->trackShipment('00340434292135100148');
+
+    expect($result)->toHaveKey('success', true)
+        ->and($result['status'])->toBe('delivered');
+
+    Http::assertSentCount(2);
+});
+
+it('gives up after the configured number of attempts and reports the status once', function () {
+    Http::fake([
+        'api-eu.dhl.com/track/shipments*' => Http::response(['title' => 'Internal Server Error'], 500),
+    ]);
+
+    $result = (new DhlTrackingService)->trackShipment('00340434292135100148');
+
+    expect($result)->toHaveKey('success', false)
+        ->toHaveKey('http_status', 500);
+
+    Http::assertSentCount(3);
+});
+
+it('does not retry a client error', function () {
+    Http::fake([
+        'api-eu.dhl.com/track/shipments*' => Http::response(['title' => 'Not Found'], 404),
+    ]);
+
+    $result = (new DhlTrackingService)->trackShipment('00340434292135100148');
+
+    expect($result)->toHaveKey('not_found', true);
+
+    Http::assertSentCount(1);
+});