Add schema enhancements for uploads, artifacts, and audit tracking

CHANGELOG.md

@@ -7,6 +7,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- Added `format` and `platform` fields to packages table (#16)
+- Added `checksum_md5` and `metadata` JSONB fields to artifacts table (#16)
+- Added `updated_at` field to tags table (#16)
+- Added `tag_name`, `user_agent`, `duration_ms`, `deduplicated`, `checksum_verified` fields to uploads table (#16)
+- Added `change_type` field to tag_history table (#16)
+- Added composite indexes for common query patterns (#16)
+- Added GIN indexes on JSONB fields for efficient JSON queries (#16)
+- Added partial index for public projects (#16)
+- Added database triggers for `updated_at` timestamps (#16)
+- Added database triggers for maintaining artifact `ref_count` accuracy (#16)
+- Added CHECK constraints for data integrity (`size > 0`, `ref_count >= 0`) (#16)
+- Added migration script `002_schema_enhancements.sql` for existing databases (#16)
+
 ## [0.1.0] - 2025-12-12
 ### Changed
 - Changed the Dockerfile npm build arg to use the deps.global.bsf.tools URL as the default registry (#45)