feat: add favicon and PWA icons (hexagon V, purple brand)

- favicon.ico (16+32+48px)
- favicon-16/32/48.png
- apple-touch-icon.png (180px)
- icon-192/512.png for PWA manifest
- site.webmanifest for installable PWA

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

public/index.html

@@ -4,6 +4,12 @@
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>VanityOnTour Status</title>
+  <link rel="icon" type="image/x-icon" href="/favicon.ico">
+  <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32.png">
+  <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16.png">
+  <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png">
+  <link rel="manifest" href="/site.webmanifest">
+  <meta name="theme-color" content="#7c3aed">
   <style>
     :root {
       --bg:       #0f0f13;

public/site.webmanifest

@@ -0,0 +1,13 @@
+{
+  "name": "VanityOnTour Status",
+  "short_name": "VoT Status",
+  "description": "Status aller VanityOnTour Dienste, Domains und der iOS App",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#0f0f13",
+  "theme_color": "#7c3aed",
+  "icons": [
+    { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png" },
+    { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png", "purpose": "any maskable" }
+  ]
+}