fix: use middleware instead of get for SPA fallback

src/server/app.ts

@@ -68,7 +68,7 @@ app.get('/health', (req, res) => {
 });
 
 // SPA fallback - must be last
-app.get('*', (req, res) => {
+app.use((req, res, next) => {
     res.sendFile(path.join(distPath, 'index.html'));
 });