No access keys in CI
Replacing long-lived AWS access keys in CI with OIDC federation, so the pipeline mints a short-lived token instead of holding a secret.

Replacing long-lived AWS access keys in CI with OIDC federation, so the pipeline mints a short-lived token instead of holding a secret.

Running OpenSSF Scorecard on a Go project flagged mutable action tags, over-broad workflow token permissions, and a missing maintenance signal.
