feat: implement complete CMT backend with API endpoints and test suite

- Add 7 core API endpoints: users, transactions, partners, products, inventory, payments, credit
- Implement role-based authentication (admin/write/read-only access)
- Add comprehensive database models with proper relationships
- Include full test coverage for all endpoints and business logic
- Set up Alembic migrations and Docker configuration
- Configure FastAPI app with CORS and database integration

backend/scripts/create_admin.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+"""
+Script to create an initial admin user for the CMT system.
+Run this after setting up the database to create the first admin user.
+"""
+
+import sys
+import os
+
+# Add the parent directory to the path so we can import from app
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from sqlmodel import Session
+from app.core.db import engine
+from app.core.auth import get_password_hash
+from app.schemas.models import User
+from app.schemas.base import UserRole
+
+
+def create_admin_user():
+    """Create an initial admin user."""
+    
+    username = input("Enter admin username: ").strip()
+    if not username:
+        print("Username cannot be empty!")
+        return
+    
+    password = input("Enter admin password: ").strip()
+    if not password:
+        print("Password cannot be empty!")
+        return
+    
+    # Hash the password
+    hashed_password = get_password_hash(password)
+    
+    # Create the user
+    admin_user = User(
+        username=username,
+        password_hash=hashed_password,
+        role=UserRole.ADMIN
+    )
+    
+    try:
+        with Session(engine) as session:
+            # Check if user already exists
+            from sqlmodel import select
+            statement = select(User).where(User.username == username)
+            existing = session.exec(statement).first()
+            if existing:
+                print(f"User '{username}' already exists!")
+                return
+            
+            session.add(admin_user)
+            session.commit()
+            session.refresh(admin_user)
+            
+            print(f"✅ Admin user '{username}' created successfully!")
+            print(f"User ID: {admin_user.id}")
+            print(f"Role: {admin_user.role}")
+            
+    except Exception as e:
+        print(f"❌ Error creating admin user: {e}")
+
+
+if __name__ == "__main__":
+    print("=== CMT Admin User Creation ===")
+    create_admin_user()