feat(microvm): add microvm example

[edersonbrilhante]

Description

Adds the regional Lambda MicroVM foundation module, example, and image-build prerequisites.

• Creates the encrypted artifact storage, build and operator IAM roles, Lambda Network Connectors, connector security groups, runtime usage policy, and propagation dependencies.
• Adds the microvm-foundation example and documentation for provisioning the regional prerequisites required by MicroVM images.
• Adds the MicroVM Ubuntu image-builder configuration, scripts, service setup, and Packer assets.
• Updates the Terraform, MiniStack, Packer, and documentation workflows for the foundation and image-build paths.

Test Plan

• Terraform formatting, initialization, and validation for the foundation module and examples.
• Provider and module tests included in the affected Terraform modules.
• Terraform commit hooks, TFLint, conflict checks, and git diff --check.
• No live AWS deployment was performed.

Related Issues

• Stacked on feat(microvm): add Terraform provider #5413.
• Follow-up runtime provider implementation: feat(compute-providers): add Lambda MicroVM provider #5255.

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[guicaulada]

I think we may be missing the runner supervisor in this image. The hook in #5280 launches /opt/microvm/entrypoint.sh run, but I could only find image-entrypoint.sh here, which starts the hook server itself. The hook ZIP also seems to contain only server.js and package.json.

Unless that supervisor comes from somewhere else, I think the launch would fail with ENOENT. Maybe we should include the script that consumes the JIT document on stdin and signals ready\n on fd 3, then check that the assembled image can start a runner. Am I overlooking another step that supplies it?