Add demo orders creation scripts

- Created management command for generating demo orders
- Added SQL script to create 25 orders with random dates (±15 days)
- Added Python runner script for executing SQL
- Demo orders include varied statuses, payment methods, and delivery types
- Orders distributed across different dates for testing date filter

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

myproject/run_demo_orders.py

@@ -0,0 +1,24 @@
+"""
+Скрипт для создания демо-заказов напрямую через SQL
+"""
+import os
+import django
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'myproject.settings')
+django.setup()
+
+from django.db import connection
+
+# Читаем SQL скрипт
+with open('create_demo_orders.sql', 'r', encoding='utf-8') as f:
+    sql = f.read()
+
+# Выполняем SQL
+with connection.cursor() as cursor:
+    try:
+        cursor.execute(sql)
+        print("[OK] SQL script executed successfully!")
+        print("[OK] 25 demo orders created!")
+    except Exception as e:
+        print(f"[ERROR] {e}")
+        raise