Cognito User Groups are vulnerable to unintended deletion on list reordering

[catrielg]

Problem

The current Cognito user group implementation uses Terraform's count meta-argument with a list of groups. This makes the resources sensitive to list order changes, potentially causing unintended group deletions when the order is modified.

Impact

• Accidental group deletions can occur during routine configuration updates
• User group memberships are lost when groups are recreated
• Potential service disruption for users relying on group-based permissions

Solution

A fix has been proposed in PR #160 which:

• Switches from count to for_each using group names as stable identifiers
• Maintains existing functionality while preventing order-based recreations
• Includes migration steps to safely handle the transition