GUI UX, secret visibility, browser-friendly hooks, deploy script

GUI:
- URL column in endpoint grid + Copy URL toolbar button so the full
  http://host:port/hook/<slug> is one click away
- Double-click a row to open the edit dialog
- Bearer/HMAC sections in the editor hide when the auth mode doesn't
  use them, and reappear with previously-entered values when switched
  back
- Log panel auto-scroll checkbox (default on) plus 3s polling so log
  entries stream in without manual refresh
- Secret fields are now plain text with a Copy button. Anyone who can
  open the admin-pipe-ACL'd GUI is already SYSTEM-equivalent on the
  host, so masking the value just made recovery harder. PFX password
  in Server Settings gets the same treatment.

Service:
- Admin pipe ops log info-level lines on every mutation
  (create/update/delete/enable/disable/update-config/bind-https) so
  GUI activity is visible in the Serilog file
- /hook/{slug} accepts GET as well as POST so a browser smoke-test
  works without curl
- /favicon.ico returns 204 so browser hits don't pollute logs with 404s
- AdminPipeServer no longer strips plaintext secrets when sending
  config to the GUI; the pipe ACL already restricts to SYSTEM/Admins

Scripts:
- New deploy.ps1: stops + republishes + copies binaries to
  C:\Program Files\WebhookServer + (re)installs the Windows Service
- install-service.ps1 now uses sc.exe argv splatting consistently for
  both create and config paths

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

src/WebhookServer.Gui/Converters/Converters.cs

@@ -13,6 +13,21 @@ public sealed class NullToBoolConverter : IValueConverter
         => throw new NotSupportedException();
 }
 
+public sealed class HookUrlConverter : IMultiValueConverter
+{
+    public object Convert(object[] values, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (values.Length < 2) return "";
+        var slug = values[0] as string ?? "";
+        var baseUrl = values[1] as string ?? "";
+        if (string.IsNullOrEmpty(baseUrl) || string.IsNullOrEmpty(slug)) return "";
+        return $"{baseUrl.TrimEnd('/')}/hook/{slug}";
+    }
+
+    public object[] ConvertBack(object? value, Type[] targetTypes, object? parameter, CultureInfo culture)
+        => throw new NotSupportedException();
+}
+
 public sealed class StringEqualsConverter : IValueConverter
 {
     public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)