docs: update release notes for 5.1.0 with dotnet path fix

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: natemcmaster

CHANGELOG.md

@@ -5,7 +5,11 @@
 ### Features
 * [@Chris-Wolfgang]: Add support for keyed dependency injection via `[FromKeyedServices]` attribute ([#560])
 
+### Fixes
+* [@claude]: Validate dotnet path exists before returning from `TryFindDotNetExePath` ([#600])
+
 [#560]: https://github.com/natemcmaster/CommandLineUtils/pull/560
+[#600]: https://github.com/natemcmaster/CommandLineUtils/issues/600
 
 ## [v5.0.1](https://github.com/natemcmaster/CommandLineUtils/compare/v5.0.0...v5.0.1)
 

src/CommandLineUtils/releasenotes.props

@@ -5,6 +5,9 @@ Changes since 5.0:
 
 Features:
 * @Chris-Wolfgang: Add support for keyed dependency injection via [FromKeyedServices] attribute (#560)
+
+Fixes:
+* @claude: Validate dotnet path exists before returning from TryFindDotNetExePath (#600)
     </PackageReleaseNotes>
     <PackageReleaseNotes Condition="$(VersionPrefix.StartsWith('5.0.'))">
 Changes since 4.1: