docs: Fix version formatting in logs and add agent guidelines

Author: rickhohler

AGENTS.md

@@ -0,0 +1,4 @@
+# Agent Guidelines
+
+## Release Management
+- **Tagging**: Always use a leading "v" for release tags (e.g., `v1.0.0`, `v1.1.0`).

CHANGELOG.md

@@ -25,7 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Security
 - N/A
 
-## [1.1.1] - 2025-12-12
+## [v1.4.0] - 2025-12-12
 
 ### Added
 - `Data` extensions for convenient SHA256 hashing (`sha256`, `sha256Hex`)
@@ -37,6 +37,25 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed compiler warnings in `MergerTests` regarding `Sendable` conformance and unnecessary `await`
 - Fixed type mismatch errors in `HashComputationTests`
 
+## [v1.3.0] - 2025-12-12
+
+### Changed
+- Bumped version to 1.3.0
+
+## [v1.2.2] - 2025-12-12
+
+### Added
+- `Codable` conformance to `HashAlgorithm`
+
+## [v1.2.1] - 2025-12-12
+
+### Fixed
+- Restructured `HashComputation` to root level for proper exports
+
+## [v1.2.0] - 2025-12-12
+
+### Added
+- HashComputation feature
 
 ## [1.1.0] - 2025-12-04