Update build pipeline to GitVersion 6.6.x and hosted agent

- Migrate from UseGitVersion@5 to gitversion/setup@3 + gitversion/execute@3
- Switch from self-hosted pool to windows-latest
- Add full checkout with fetchDepth: 0 and fetchTags
- Add tag build workaround for GitVersion detached HEAD issue
- Build via solution file instead of individual csproj files

Author: fw2568

azure-pipelines.yml

@@ -8,15 +8,41 @@ trigger:
 - refs/tags/v*
 
 pool:
-  name: 'default'
+  vmImage: windows-latest
+
 
 variables:
   buildConfiguration: 'Release'
 
 steps:
-- task: UseGitVersion@5
+- checkout: self
+  clean: true
+  fetchDepth: 0
+  fetchTags: true
+
+- task: gitversion/setup@3
   inputs:
-    versionSpec: '5.11.x'
+    versionSpec: '6.6.x'
+
+# Workaround: Azure DevOps sets BUILD_SOURCEBRANCH to refs/tags/... for tag builds,
+# causing GitVersion to fail in detached HEAD mode (see https://github.com/GitTools/GitVersion/issues/4534).
+# Setting GIT_BRANCH to the branch containing the tag lets GitVersion resolve the version correctly.
+- powershell: |
+    $sourceBranch = "$(Build.SourceBranch)"
+    if ($sourceBranch.StartsWith("refs/tags/")) {
+        $tagCommit = git rev-list -n 1 "$sourceBranch"
+        $containingBranch = git branch -r --contains $tagCommit |
+            Where-Object { $_ -match 'origin/(main|master)' } |
+            Select-Object -First 1
+        if ($containingBranch) {
+            $branchName = $containingBranch.Trim().Replace("origin/", "")
+            Write-Host "Tag build detected - setting GIT_BRANCH to refs/heads/$branchName"
+            Write-Host "##vso[task.setvariable variable=GIT_BRANCH]refs/heads/$branchName"
+        }
+    }
+  displayName: 'Resolve branch for tag builds'
+
+- task: gitversion/execute@3
 
 - task: DotNetCoreCLI@2
   inputs:
@@ -26,7 +52,7 @@ steps:
   displayName: Build
   inputs:
     command: build
-    projects: '**/*.csproj'
+    projects: '**/*.sln'
     arguments: '--configuration $(buildConfiguration)'
 
 - task: DotNetCoreCLI@2
@@ -52,4 +78,4 @@ steps:
     command: 'push'
     packagesToPush: '$(Build.ArtifactStagingDirectory)/**/*.nupkg;!$(Build.ArtifactStagingDirectory)/**/*.symbols.nupkg'
     nuGetFeedType: 'internal'
-    publishVstsFeed: '59a3608a-9bed-4cb4-9467-6efaaa3cbef5/1e425ef4-e3a0-4927-b4c0-2beff753cb88'  
+    publishVstsFeed: '59a3608a-9bed-4cb4-9467-6efaaa3cbef5/1e425ef4-e3a0-4927-b4c0-2beff753cb88'