Request for review: Neptune GlobalCluster L2 support (#38221)

[masterhugo]

Hi team

I wanted to ask for a hand reviewing #38221, which adds L2 support for AWS::Neptune::GlobalCluster in the alpha Neptune module. It closes issue #27988, which has community requests for multi-region replicas.

A quick summary to make review easier:

What it adds: a GlobalCluster construct (create a new global database or adopt an existing cluster as primary via sourceCluster), a fromGlobalClusterIdentifier import method, and DatabaseClusterProps.globalCluster so a cluster can join a global database.
New permissions: none.
Validation: unit tests (defaults, source cluster, validations, token-safety, tags, import), an integration test with a snapshot, and README docs verified with Rosetta. Build, awslint, ESLint, and the full unit suite all pass.
Status: rebased against main several times to keep it current (most recently today).

I know the team has a large PR backlog, so I understand if it takes time — I just wanted to make sure it doesn't get lost in the volume, given it's already labeled p2 / effort/medium with no pending changes on my end. Any feedback (even "this needs X before anyone looks closely") would help a lot.

Thanks for the work you all put into maintaining the project!

[otaviomacedo]

I've left some comments there.

[masterhugo]

Hi @otaviomacedo, thanks for the review! Apologies for the delay, I was on vacation and am just now getting back to it. I'll go through both of your comments and follow up shortly.