fix: update branding assets, favicon, and correct Overseerr→Jellyseerr in showcase

- Update brand logo images (dark/light variants)
- Replace favicon.ico with optimized version, remove redundant icon.jpg
- Fix Navbar logo dimensions (h-14 for better visibility)
- Remove dead link from installation docs
- Correct AppShowcase: Overseerr → Jellyseerr (template renamed in codebase)
- Rebuild static export

src/app/docs/installation/page.tsx

@@ -71,12 +71,6 @@ export default function DocsInstallationPage() {
           </table>
         </div>
 
-        <blockquote className="border-l-4 border-brand-500/50 bg-brand-500/5 p-4 rounded-r-lg mt-6">
-          <p className="text-surface-300">
-            <strong className="text-brand-400">Note:</strong> DashCaddy can run on Windows and macOS for development, but production deployments should target Linux. Docker Desktop works for testing but is not recommended for production workloads.
-          </p>
-        </blockquote>
-
         <h2>Quick start with start.sh</h2>
         <p>
           The fastest path to a running DashCaddy is the bundled <code>start.sh</code> script. It performs environment