feat(microvm): add foundation module example

[edersonbrilhante]

Description

Adds the regional Lambda MicroVM foundation module and example. The module
creates the encrypted artifact bucket, build and operator IAM roles, native
Lambda Network Connectors, connector security groups, runtime usage policy,
and propagation dependencies. The example shows how to configure and apply
the foundation before running a MicroVM image build.

The module uses the native aws_lambdacore_network_connector resource and
requires AWS provider 6.61 or newer. The build and runtime usage policies each
accept a dedicated *_policy_name_prefix, while the build and Network
Connector operator roles each accept a dedicated *_role_name_prefix; all use
Terraform's IAM name_prefix attribute.

Test Plan

• terraform fmt -recursive -check -diff modules/microvm-foundation examples/microvm-foundation
• terraform init -backend=false -input=false for the module and example
• terraform validate for the module and example
• Terraform commit hooks, including TFLint and conflict checks
• git diff --check

Related Issues

Depends on #5363.

[github-actions]

Dependency Review

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

Scanned Files

None