Update Changelog.md for 3.4.2 release

Author: LinkDotNet Bot

CHANGELOG.md

@@ -6,6 +6,8 @@ All notable changes to **ValueStringBuilder** will be documented in this file. T
 
 ## [Unreleased]
 
+## [3.4.2] - 2026-07-04
+
 ### Fixed
 
 - Resolved `CS0121` overload ambiguity when passing a no-hole interpolated string (e.g. `Append($"text")`) to `Append`/`AppendLine` on C# 13 and earlier, by adding `Append(string?)` and `AppendLine(string?)` overloads. Reported by [@SMAH1](https://github.com/SMAH1) in #283
@@ -543,7 +545,8 @@ This release brings extensions to the `ValueStringBuilder` API. For `v1.0` the `
 
 - Initial release
 
-[unreleased]: https://github.com/linkdotnet/StringBuilder/compare/3.4.1...HEAD
+[unreleased]: https://github.com/linkdotnet/StringBuilder/compare/3.4.2...HEAD
+[3.4.2]: https://github.com/linkdotnet/StringBuilder/compare/3.4.1...3.4.2
 [3.4.1]: https://github.com/linkdotnet/StringBuilder/compare/3.4.0...3.4.1
 [3.4.0]: https://github.com/linkdotnet/StringBuilder/compare/3.3.0...3.4.0
 [3.3.0]: https://github.com/linkdotnet/StringBuilder/compare/3.2.0...3.3.0