Add VPS health endpoint

src/main/java/com/litoralregas/vpnprovisioner/vps/WireGuardVpsService.java

@@ -21,7 +21,7 @@ public class WireGuardVpsService {
 
     public Set<String> findUsedVpnIps() {
         SshCommandResult result = sshService.executeOnConfiguredVps(
-                "sudo wg show wg0 allowed-ips"
+                "sudo /usr/local/sbin/lr-wg-used-ips"
         );
 
         if (result.exitCode() != 0) {
@@ -65,4 +65,18 @@ public class WireGuardVpsService {
                 true
         );
     }
+
+    public String getVpsHealthJson() {
+        SshCommandResult result = sshService.executeOnConfiguredVps(
+                "sudo /usr/local/sbin/lr-vps-health"
+        );
+
+        if (result.exitCode() != 0) {
+            throw new SshCommandException(
+                    "Failed to query VPS health: " + result.stderr()
+            );
+        }
+
+        return result.stdout();
+    }
 }