Fix S3 client to support IRSA credentials (#54)

Only pass explicit credentials to boto3 if they're actually set.
This allows the default credential chain (including IRSA web identity
tokens) to be used when no access key is configured.

Also adds CHANGELOG entries for AWS services configuration.

CHANGELOG.md

@@ -6,6 +6,23 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- Added AWS Secrets Manager CSI driver support for database credentials (#54)
+- Added SecretProviderClass template for Secrets Manager integration (#54)
+- Added IRSA service account annotations for prod and stage environments (#54)
+
+### Changed
+- Configured stage and prod to use AWS RDS instead of PostgreSQL subchart (#54)
+- Configured stage and prod to use AWS S3 instead of MinIO subchart (#54)
+- Changed prod deployment from manual to automatic on version tags (#54)
+- Updated S3 client to support IRSA credentials when no explicit keys provided (#54)
+- Changed prod image pullPolicy to Always (#54)
+- Added proxy-body-size annotation to prod ingress for large uploads (#54)
+
+### Removed
+- Disabled PostgreSQL subchart for stage and prod environments (#54)
+- Disabled MinIO subchart for stage and prod environments (#54)
+
 ### Added
 - Added comprehensive upload/download tests for size boundaries (1B to 1GB) (#38)
 - Added concurrent upload/download tests (2, 5, 10 parallel operations) (#38)