Improve error messaging for startup database error

ts/util/getAppErrorIcon.ts

@@ -0,0 +1,17 @@
+// Copyright 2025 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { nativeImage } from 'electron';
+import type { NativeImage } from 'electron';
+import { join } from 'path';
+
+export function getAppErrorIcon(): NativeImage {
+  const iconPath = join(
+    __dirname,
+    '..',
+    '..',
+    'images',
+    'app-icon-with-error.png'
+  );
+  return nativeImage.createFromPath(iconPath);
+}