V1.5.0: Version bump + Download-Button Redesign

- Version auf 1.5.0 in allen Packages, CI, Dockerfile, Electron
- Download-Button im gleichen Design wie Version-Badge (bg-secondary, radius, hover accent)
- CI Registry auf adriahub (192.168.1.100:9080) umgestellt

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

web/src/App.tsx

@@ -91,7 +91,7 @@ export default function App() {
     return () => { es?.close(); clearTimeout(retryTimer); };
   }, []);
 
-  const version = (import.meta as any).env?.VITE_APP_VERSION ?? '1.0.0';
+  const version = (import.meta as any).env?.VITE_APP_VERSION ?? '1.5.0';
 
   // Tab icon mapping
   const tabIcons: Record<string, string> = {
@@ -137,7 +137,8 @@ export default function App() {
               download
               title="Desktop App herunterladen"
             >
-              {'\u2B07\uFE0F'}
+              <span className="hub-download-icon">{'\u2B07\uFE0F'}</span>
+              <span className="hub-download-label">Desktop App</span>
             </a>
           )}
           <span className="hub-version">v{version}</span>