Add coupons, newsletter, country-based shipping, sale prices, USP bar

- Gutscheincodes: DB-Verwaltung (%, €-Rabatt, Mindestbestellwert, Ablauf),
  Eingabefeld im Checkout, Admin unter Marketing → Gutscheine
- Newsletter: Double-Opt-In per E-Mail, Formular im Footer,
  Admin-Liste mit CSV-Export
- Länderzonen-Versand: DE / DACH / EU / WORLD, Versandkosten nach
  Lieferland dynamisch berechnet, Coupon-Rabatt in Bestellung gespeichert
- Sale-Preise: sale_price auf Produkten, durchgestrichener UVP auf
  Produktkarte, Sonderangebote-Sektion auf Startseite
- USP-Leiste auf Startseite: Versand, Zahlung, Rückgabe, Service

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

database/migrations/2024_01_01_000019_create_coupons_table.php

@@ -0,0 +1,36 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::create('coupons', function (Blueprint $table) {
+            $table->id();
+            $table->string('code')->unique();
+            $table->enum('type', ['percent', 'fixed'])->default('fixed');
+            $table->decimal('value', 10, 2);
+            $table->decimal('min_order_value', 10, 2)->nullable();
+            $table->timestamp('expires_at')->nullable();
+            $table->unsignedInteger('max_uses')->nullable();
+            $table->unsignedInteger('used_count')->default(0);
+            $table->boolean('active')->default(true);
+            $table->timestamps();
+        });
+
+        Schema::table('orders', function (Blueprint $table) {
+            $table->string('coupon_code')->nullable()->after('payment_method');
+            $table->decimal('discount_amount', 10, 2)->default(0)->after('coupon_code');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('orders', function (Blueprint $table) {
+            $table->dropColumn(['coupon_code', 'discount_amount']);
+        });
+        Schema::dropIfExists('coupons');
+    }
+};

database/migrations/2024_01_01_000020_create_newsletter_subscribers_table.php

@@ -0,0 +1,23 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::create('newsletter_subscribers', function (Blueprint $table) {
+            $table->id();
+            $table->string('email')->unique();
+            $table->string('token', 64)->nullable();
+            $table->timestamp('confirmed_at')->nullable();
+            $table->timestamps();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('newsletter_subscribers');
+    }
+};

database/migrations/2024_01_01_000021_add_sale_price_to_products.php

@@ -0,0 +1,21 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::table('products', function (Blueprint $table) {
+            $table->decimal('sale_price', 10, 2)->nullable()->after('base_price');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('products', function (Blueprint $table) {
+            $table->dropColumn('sale_price');
+        });
+    }
+};