fix: local fonts via @fontsource, favicon, autocomplete attrs

- Replace Google Fonts with @fontsource/dm-sans and @fontsource/jetbrains-mono
- Add SVG favicon
- Add autocomplete attributes to login/setup form inputs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/app.html

@@ -4,9 +4,6 @@
 		<meta charset="utf-8" />
 		<meta name="viewport" content="width=device-width, initial-scale=1" />
 		<link rel="icon" type="image/svg+xml" href="/favicon.svg" />
-		<link rel="preconnect" href="https://fonts.googleapis.com" />
-		<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
-		<link href="https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300..700;1,9..40,300..700&family=JetBrains+Mono:wght@400;500;600&display=swap" rel="stylesheet" />
 		<title>Notify Bridge</title>
 		%sveltekit.head%
 	</head>