Prepare v2.3.1 release notes

Author: chammoru

CHANGELOG.md

@@ -8,6 +8,10 @@ the [GitHub Releases page](https://github.com/chammoru/Q1View/releases).
 
 ## [Unreleased]
 
+---
+
+## [2.3.1] — 2026-06-05
+
 ### Fixed
 - Comparator: LPIPS model downloads now honor the current user's Windows proxy,
   PAC, and auto-detect settings in addition to the WinHTTP default proxy.
@@ -282,7 +286,8 @@ the [GitHub Releases page](https://github.com/chammoru/Q1View/releases).
 
 ---
 
-[Unreleased]: https://github.com/chammoru/Q1View/compare/v2.3.0...HEAD
+[Unreleased]: https://github.com/chammoru/Q1View/compare/v2.3.1...HEAD
+[2.3.1]: https://github.com/chammoru/Q1View/compare/v2.3.0...v2.3.1
 [2.3.0]: https://github.com/chammoru/Q1View/compare/v2.2.0...v2.3.0
 [2.2.0]: https://github.com/chammoru/Q1View/compare/v2.1.0...v2.2.0
 [2.1.0]: https://github.com/chammoru/Q1View/compare/v2.0.0...v2.1.0