Standardize Terraform module versioning and release process

[winkletinkle]

As teams start consuming our modules we need a versioning strategy.

Proposal:

• Semver via Git tags (v1.0.0)
• Each module under modules/<name>/
• CHANGELOG.md per module
• terraform-docs on every PR
• Terratest for integration tests
• GitHub Actions: fmt, validate, tflint, terratest

Looking for input before drafting the contributing guide.

[hamza-mohd]

Solid. One non-negotiable: pin versions in all example code (?ref=v1.0.0). Floating main references have broken prod pipelines before - a breaking change lands and suddenly all consumers are impacted.

[arjunmehta-git]

Add terraform fmt -check and tflint as pre-commit hooks too. Faster feedback than waiting for CI. I'll add .pre-commit-config.yaml.

[sarajkrishnasingh]

For Terratest - real AWS sandbox for merge checks, LocalStack for PR drafts? LocalStack is faster and free but won't catch IAM/SCP issues. I'd say that tradeoff is acceptable.