Update favicon links and Open Graph/Twitter image metadata in index.html for improved branding and social sharing. Replace existing favicon with multiple formats and update image references for better compatibility across platforms.

frontend/index.html

@@ -2,8 +2,15 @@
 <html lang="de">
   <head>
     <meta charset="UTF-8" />
-    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    
+    <!-- Favicons -->
+    <link rel="icon" type="image/x-icon" href="/favicon.ico" />
+    <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png" />
+    <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png" />
+    <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png" />
+    <link rel="manifest" href="/site.webmanifest" />
+    
     <title>Trainingstagebuch – Vereinsverwaltung, Trainingsplanung & Turniere</title>
     <meta name="description" content="Das TrainingsTagebuch hilft Vereinen und Trainer:innen, Mitglieder zu verwalten, Trainings zu dokumentieren, Spielpläne zu organisieren und Statistiken auszuwerten – alles in einer modernen Web‑App." />
     <link rel="canonical" href="https://tt-tagebuch.de/" />
@@ -14,13 +21,13 @@
     <meta property="og:title" content="Trainingstagebuch – Vereinsverwaltung, Trainingsplanung & Turniere" />
     <meta property="og:description" content="Mitgliederverwaltung, Trainingstagebuch, Spiel‑ und Turnierorganisation sowie Statistiken – DSGVO‑freundlich und einfach." />
     <meta property="og:url" content="https://tt-tagebuch.de/" />
-    <meta property="og:image" content="https://tt-tagebuch.de/vite.svg" />
+    <meta property="og:image" content="https://tt-tagebuch.de/android-chrome-512x512.png" />
 
     <!-- Twitter -->
     <meta name="twitter:card" content="summary_large_image" />
     <meta name="twitter:title" content="Trainingstagebuch – Vereinsverwaltung, Trainingsplanung & Turniere" />
     <meta name="twitter:description" content="Mitgliederverwaltung, Trainingstagebuch, Spiel‑ und Turnierorganisation sowie Statistiken – DSGVO‑freundlich und einfach." />
-    <meta name="twitter:image" content="https://tt-tagebuch.de/vite.svg" />
+    <meta name="twitter:image" content="https://tt-tagebuch.de/android-chrome-512x512.png" />
 
     <!-- JSON-LD: Website + Organization -->
     <script type="application/ld+json">

frontend/public/site.webmanifest

@@ -0,0 +1 @@
+{"name":"","short_name":"","icons":[{"src":"/android-chrome-192x192.png","sizes":"192x192","type":"image/png"},{"src":"/android-chrome-512x512.png","sizes":"512x512","type":"image/png"}],"theme_color":"#ffffff","background_color":"#ffffff","display":"standalone"}

frontend/src/assets/favicon_io/site.webmanifest

@@ -0,0 +1 @@
+{"name":"","short_name":"","icons":[{"src":"/android-chrome-192x192.png","sizes":"192x192","type":"image/png"},{"src":"/android-chrome-512x512.png","sizes":"512x512","type":"image/png"}],"theme_color":"#ffffff","background_color":"#ffffff","display":"standalone"}