Research Terraform resilience for AWS: region, instance type, and subscription restrictions

Parent Issue

Sub-issue of #95

Goal

Research what options exist to make the AWS Terraform deployment more resilient for users with restricted accounts (e.g., limited regions, instance type quotas, organization SCPs).

Research Areas

• What AWS regions are commonly restricted for educational/free-tier accounts?
• Can we provide a sensible list of fallback regions or let users easily override?
• Are there instance types more universally available across accounts (e.g., t3.micro vs t2.micro)?
• How do AWS Organizations SCPs or IAM boundaries commonly affect Terraform deployments?
• Can we add Terraform validation or pre-flight checks to surface issues early?

Deliverables

• Document findings in this issue
• Recommend whether changes are worth implementing for AWS
• If yes, propose specific Terraform variable defaults, validation rules, or fallback logic

Notes

Even if no changes are needed, document why so future contributors don't re-investigate.

Start by reviewing the AWS Terraform deployment and the restrictions listed in this issue: regions, instance types, SCPs, IAM boundaries, and pre-flight validation. Document findings in this issue, explain whether changes are worthwhile, and record any recommended defaults, validation rules, or fallback logic, including why no changes are needed if that is the conclusion.