Add favicon and logo — three stacked drive bays with green LEDs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

templates/login.html

@@ -3,6 +3,7 @@
 <head>
     <meta charset="UTF-8">
     <title>MicroNAS — Login</title>
+    <link rel="icon" type="image/svg+xml" href="{{ url_for('static', filename='img/favicon.svg') }}">
     <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5/dist/css/bootstrap.min.css">
     <link rel="stylesheet" href="{{ url_for('static', filename='css/app.css') }}">
     <style>