Installer: synchronous service stop + kill stray GUI/Service processes

The previous sc.exe stop is fire-and-forget; on slower machines the
file-copy step started before the service had actually released its
binaries, leaving the upgrade in a broken state. Switch to net.exe
stop which blocks until the service reports STOPPED.

Also taskkill any running WebhookServer.Gui.exe (the user might have
left the tray running) and any orphan WebhookServer.Service.exe (from
deploy.ps1 dev runs) so all copies of the binaries are unlocked
before [Files] runs.

Pre-flight ServiceExists() check via sc query so the installer only
calls "net stop" when there is actually a service to stop, rather
than relying on net's error code.

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

Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
 
   <PropertyGroup>
-    <Version>0.1.0</Version>
+    <Version>0.1.1</Version>
     <Authors>Justin Paul</Authors>
     <Company>Justin Paul</Company>
     <Product>Webhook Server</Product>

installer/webhook-server.iss

@@ -77,3 +77,41 @@ Filename: "powershell.exe"; \
     Parameters: "-NoProfile -ExecutionPolicy Bypass -File ""{app}\scripts\uninstall-service.ps1"""; \
     Flags: runhidden; \
     RunOnceId: "RemoveWebhookService"
+
+[Code]
+function ServiceExists(): Boolean;
+var
+  ResultCode: Integer;
+begin
+  // sc.exe query returns 0 when the service exists, 1060 when it does not.
+  Exec(ExpandConstant('{sys}\sc.exe'), 'query WebhookServer', '', SW_HIDE,
+       ewWaitUntilTerminated, ResultCode);
+  Result := (ResultCode = 0);
+end;
+
+function PrepareToInstall(var NeedsRestart: Boolean): String;
+var
+  ResultCode: Integer;
+begin
+  Result := '';
+
+  // 1. If the service exists, stop it so its binaries are unlocked before file
+  //    copy. net stop is synchronous (blocks until the service is actually
+  //    stopped), unlike sc stop which is fire-and-forget. Non-zero exit -
+  //    already stopped, missing, dependency error - we ignore; the file copy
+  //    will fail loudly if the binaries are still locked.
+  if ServiceExists() then
+  begin
+    WizardForm.PreparingLabel.Caption := 'Stopping the WebhookServer service...';
+    Exec(ExpandConstant('{sys}\net.exe'), 'stop WebhookServer', '', SW_HIDE,
+         ewWaitUntilTerminated, ResultCode);
+  end;
+
+  // 2. Kill any running GUI / tray instances so their binaries are unlocked too.
+  //    /f forces termination, /im matches by image name, "*" wildcard would be
+  //    risky so we name them explicitly.
+  Exec(ExpandConstant('{sys}\taskkill.exe'), '/f /im WebhookServer.Gui.exe',
+       '', SW_HIDE, ewWaitUntilTerminated, ResultCode);
+  Exec(ExpandConstant('{sys}\taskkill.exe'), '/f /im WebhookServer.Service.exe',
+       '', SW_HIDE, ewWaitUntilTerminated, ResultCode);
+end;

src/WebhookServer.Gui/MainWindow.xaml

@@ -29,8 +29,9 @@
                 <Separator/>
                 <MenuItem Header="_Import config…" Command="{Binding ImportConfigCommand}"/>
                 <MenuItem Header="_Export config…" Command="{Binding ExportConfigCommand}"/>
-                <MenuItem Header="_Backups"
+                <MenuItem Header="Config _Checkpoints"
                           ItemsSource="{Binding Backups}"
+                          ToolTip="Snapshots taken automatically before each save. Click one to restore."
                           SubmenuOpened="OnBackupsSubmenuOpened">
                     <MenuItem.ItemContainerStyle>
                         <Style TargetType="MenuItem">

src/WebhookServer.Gui/ViewModels/MainViewModel.cs

@@ -189,7 +189,7 @@ public sealed partial class MainViewModel : ObservableObject
                 foreach (var b in list) Backups.Add(b);
             });
         }
-        catch { /* ignore - backup listing isn't critical */ }
+        catch { /* ignore - checkpoint listing isn't critical */ }
     }
 
     [RelayCommand]
@@ -197,8 +197,8 @@ public sealed partial class MainViewModel : ObservableObject
     {
         if (entry is null) return;
         var ok = MessageBox.Show(
-            $"Restore configuration from {entry.FileName} ({entry.SavedAt:yyyy-MM-dd HH:mm})?\n\nA backup of the current config will be saved first.",
-            "Restore backup",
+            $"Restore the configuration from the checkpoint taken at {entry.SavedAt:yyyy-MM-dd HH:mm}?\n\nThe current configuration is automatically saved as a new checkpoint first, so you can roll forward again.",
+            "Restore checkpoint",
             MessageBoxButton.OKCancel,
             MessageBoxImage.Question);
         if (ok != MessageBoxResult.OK) return;
@@ -249,7 +249,7 @@ public sealed partial class MainViewModel : ObservableObject
             if (cfg is null) throw new InvalidOperationException("File did not contain a valid config.");
 
             var ok = MessageBox.Show(
-                $"Replace the current configuration with {dlg.FileName}?\n\nA backup of the current config will be saved first.",
+                $"Replace the current configuration with {dlg.FileName}?\n\nA checkpoint of the current config is saved first, so you can roll back from File → Config Checkpoints.",
                 "Import config",
                 MessageBoxButton.OKCancel,
                 MessageBoxImage.Warning);

src/WebhookServer.Gui/WebhookServer.Gui.csproj

@@ -16,6 +16,7 @@
     <UseWPF>true</UseWPF>
     <UseWindowsForms>true</UseWindowsForms>
     <ApplicationIcon>..\..\resources\webhook-server.ico</ApplicationIcon>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
     <AssemblyTitle>Webhook Server</AssemblyTitle>
   </PropertyGroup>
 

src/WebhookServer.Gui/app.manifest

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="WebhookServer.Gui"/>
+
+  <!-- The GUI talks to the service via a named pipe ACL'd to SYSTEM and the
+       Administrators group. UAC token splitting denies that group on the
+       standard user token, so without elevation the pipe connect fails with
+       "Access is denied". Always run elevated. Start Menu shortcuts and the
+       installer's post-install launch both honor this. -->
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+    <security>
+      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v2">
+        <requestedExecutionLevel level="requireAdministrator" uiAccess="false"/>
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- Windows 10 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
+    </application>
+  </compatibility>
+</assembly>