Document cluster-admin security consideration

[maximiliantech]

Summary

The operator uses cluster-admin which should be documented as a security consideration.

Problem

• pkg/resources/platform/cluster_role_binding.go:29
• Operator bound to cluster-admin with full cluster access
• Appropriate for local kind clusters but should be documented

Suggested Fix

Add README section explaining this is designed for local development environments and should not be used on shared/production clusters without review.

Priority

Important