UI: Footer mit Version und Build-Kanal hinzugefügt (Header bleibt clean)

web/src/App.tsx

@@ -470,6 +470,15 @@ export default function App() {
             );
           })}
         </main>
+        {/* Footer: Version/Channel */}
+        <footer className="footer-info">
+          <span>
+            v{import.meta.env.VITE_APP_VERSION || ''}
+            {import.meta.env.VITE_BUILD_CHANNEL === 'nightly' && (
+              <span className="ml-2">• Nightly</span>
+            )}
+          </span>
+        </footer>
       </div>
       {showTop && (
         <button type="button" className="back-to-top" aria-label="Nach oben" onClick={()=>window.scrollTo({top:0, behavior:'smooth'})}>↑ Top</button>

web/src/styles.css

@@ -632,7 +632,12 @@ header p {
 
 .hint { opacity: .7; padding: 24px 0; }
 
-/* footer-info entfernt */
+/* Footer mit Version/Build-Kanal */
+.footer-info {
+  opacity: .7;
+  font-size: 12px;
+  padding: 16px 0 8px;
+}
 
 .tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
 .tab {