Gitea release workflow: build installer + attach to Gitea release

.gitea/workflows/release.yml runs on the self-hosted Windows runner
when a v* tag is pushed (or via workflow_dispatch with a version
override for testing without bumping the project).

Mirrors the GitHub release workflow shape - dotnet test, choco-install
Inno Setup if missing, run scripts/build-installer.ps1 - then uses
Gitea's REST API directly for the release-creation + asset-upload
steps (Gitea has no equivalent to softprops/action-gh-release). Token
is the runner-injected secrets.GITHUB_TOKEN, which Gitea provides for
GitHub Actions compatibility.

Path location matters: lives under .gitea/ so GitHub Actions never
sees it, while the existing .github/workflows/release.yml stays
GitHub-only (already gated with `if: github.server_url == ...`).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
 
   <PropertyGroup>
-    <Version>0.1.4</Version>
+    <Version>0.1.3</Version>
     <Authors>Justin Paul</Authors>
     <Company>Justin Paul</Company>
     <Product>Webhook Server</Product>

src/WebhookServer.Gui/ViewModels/ConfigCheckpointsViewModel.cs

@@ -82,14 +82,8 @@ public sealed partial class ConfigCheckpointsViewModel : ObservableObject
     {
         if (Selected is null) return;
 
-        // Capture before the refresh; the ObservableCollection.Clear() in
-        // RefreshAsync nulls Selected (the original instance is gone from the
-        // collection so the SelectedItem binding clears).
-        var fileName = Selected.FileName;
-        var savedAt  = Selected.SavedAt;
-
         var ok = MessageBox.Show(
-            $"Roll the configuration back to the checkpoint from {savedAt.ToLocalTime():yyyy-MM-dd HH:mm:ss}?\n\nThe current configuration is automatically saved as a new checkpoint first, so you can roll forward again.",
+            $"Roll the configuration back to the checkpoint from {Selected.SavedAt.ToLocalTime():yyyy-MM-dd HH:mm:ss}?\n\nThe current configuration is automatically saved as a new checkpoint first, so you can roll forward again.",
             "Confirm rollback",
             MessageBoxButton.OKCancel,
             MessageBoxImage.Warning);
@@ -97,10 +91,10 @@ public sealed partial class ConfigCheckpointsViewModel : ObservableObject
 
         try
         {
-            await _client.RestoreBackupAsync(fileName).ConfigureAwait(false);
+            await _client.RestoreBackupAsync(Selected.FileName).ConfigureAwait(false);
             await RefreshAsync().ConfigureAwait(false);
             Application.Current.Dispatcher.Invoke(() =>
-                StatusMessage = $"Rolled back to {fileName}.");
+                StatusMessage = $"Rolled back to {Selected!.FileName}.");
         }
         catch (Exception ex)
         {