feat(server): store and apply negative special price profits

Keep signed buy/sell extras so discounts work on quotes and orders, and ignore the nested user clone in this repo.

Co-authored-by: Cursor <cursoragent@cursor.com>

database/migrations/2026_08_16_000001_create_customer_special_price_packages_tables.php

@@ -12,8 +12,8 @@ return new class extends Migration
             Schema::create('customer_special_price_packages', function (Blueprint $table) {
                 $table->id();
                 $table->string('title');
-                $table->unsignedBigInteger('profit_buy')->default(0);
-                $table->unsignedBigInteger('profit_sell')->default(0);
+                $table->bigInteger('profit_buy')->default(0);
+                $table->bigInteger('profit_sell')->default(0);
                 $table->boolean('show_product')->default(true);
                 $table->boolean('is_active')->default(true);
                 $table->timestamps();

database/migrations/2026_08_17_000001_allow_negative_special_price_profits.php

@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        if (! Schema::hasTable('customer_special_price_packages')) {
+            return;
+        }
+
+        DB::statement('ALTER TABLE customer_special_price_packages MODIFY profit_buy BIGINT NOT NULL DEFAULT 0');
+        DB::statement('ALTER TABLE customer_special_price_packages MODIFY profit_sell BIGINT NOT NULL DEFAULT 0');
+    }
+
+    public function down(): void
+    {
+        if (! Schema::hasTable('customer_special_price_packages')) {
+            return;
+        }
+
+        DB::statement('ALTER TABLE customer_special_price_packages MODIFY profit_buy BIGINT UNSIGNED NOT NULL DEFAULT 0');
+        DB::statement('ALTER TABLE customer_special_price_packages MODIFY profit_sell BIGINT UNSIGNED NOT NULL DEFAULT 0');
+    }
+};