v0.3.2 — Build system: NSIS installer, Wails stubs, TS fixes

- NSIS installer script (Desktop shortcut option, German UI)
- Wails JS binding stubs for standalone frontend build
- TypeScript fixes (DownloadUpdate args, type mismatches)
- PostCSS config fix for Tailwind v3
- App icon (meal plan)

frontend/src/components/InfoPage.tsx

@@ -42,7 +42,7 @@ export function InfoPage() {
     setError(null);
     
     try {
-      await DownloadUpdate(updateInfo.download_url);
+      await DownloadUpdate();
       setDownloadComplete(true);
     } catch (err) {
       setError(err instanceof Error ? err.message : 'Fehler beim Herunterladen des Updates');