Architecture: EFS for shared storage

[scttfrdmn]

HubZero stores user-uploaded files and platform assets on local disk. This prevents horizontal scaling and makes instance replacement destructive.

Proposed changes:

• Add an EFS file system for HubZero's uploads and shared data directories
• Mount EFS on EC2 at bootstrap via userdata.sh
• Configure EFS with encryption at rest and in transit
• Add EFS security group allowing NFS (port 2049) from EC2 only
• Implement in both Terraform and CDK

Benefits:

• Data survives instance replacement (AMI refresh, scaling)
• Required prerequisite for horizontal scaling behind an ALB
• EFS automatically replicates across AZs (durability)