Address code review feedback

- Use StringComparison.Ordinal for string comparison
- Add clarifying comment for manual JSON creation in test

Co-authored-by: AArnott <[email protected]>

Author: Copilot

src/NerdBank.GitVersioning/VersionFile.cs

@@ -245,7 +245,7 @@ protected static void ApplyPrereleaseProperty(VersionOptions options)
 
         // Apply the prerelease tag to the version
         string prereleaseTag = options.Prerelease;
-        if (!prereleaseTag.StartsWith("-"))
+        if (!prereleaseTag.StartsWith("-", StringComparison.Ordinal))
         {
             // Add the hyphen prefix if not present
             prereleaseTag = "-" + prereleaseTag;

test/Nerdbank.GitVersioning.Tests/VersionFileTests.cs

@@ -811,7 +811,9 @@ public void Prerelease_ThrowsWhen_VersionAlreadyHasPrerelease()
         this.WriteVersionFile(parent);
 
         // Create a child version.json that specifies both version with prerelease AND prerelease property
-        // This creates an invalid state that should throw when read
+        // This creates an invalid state that should throw when read.
+        // Note: We manually create the JSON here (rather than using WriteVersionFile) because
+        // this is an intentionally invalid configuration that cannot be represented through the API.
         string childPath = Path.Combine(this.RepoPath, "child");
         Directory.CreateDirectory(childPath);
         string versionJsonPath = Path.Combine(childPath, "version.json");