fix: Improve condo ID handling and add error message

Prevents client-side generation of condo IDs, delegating this to the backend/service for consistency.
Introduces an alert for save condo errors and ensures the active condo is correctly updated or set.
Adds logic to auto-select the first condo if none is active.

nginx.conf

@@ -1,22 +1 @@
-server {
-    listen 80;
-    
-    # Serve i file statici del frontend
-    location / {
-        root /usr/share/nginx/html;
-        index index.html index.htm;
-        # Fondamentale per il routing client-side di React (SPA)
-        try_files $uri $uri/ /index.html;
-    }
-
-    # Proxy verso il backend
-    location /api {
-        # 'backend' è il nome del servizio definito nel docker-compose.yml
-        proxy_pass http://backend:3001;
-        proxy_http_version 1.1;
-        proxy_set_header Upgrade $http_upgrade;
-        proxy_set_header Connection 'upgrade';
-        proxy_set_header Host $host;
-        proxy_cache_bypass $http_upgrade;
-    }
-}
+<EFBFBD><EFBFBD><EFBFBD>z