feat: implement user management system

- Add role field to UserProfile (superadmin/admin/trainer)
- Add role-based permission classes
- Create UserManagementViewSet with CRUD and password change
- Add API types and components for user management
- Create users management page in settings
- Only superadmins can manage users

backend/Dockerfile

@@ -0,0 +1,23 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+ENV PYTHONDONTWRITEBYTECODE=1
+ENV PYTHONUNBUFFERED=1
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential \
+    libpq-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+COPY . .
+
+RUN mkdir -p /app/media /app/staticfiles
+
+EXPOSE 8000
+
+CMD ["gunicorn", "--bind", "0.0.0.0:8000", "--workers", "4", "--threads", "2", "--timeout", "60", "wrestleDesk.wsgi:application"]