refactor(frontend): move form-item hints from extra to tooltip

Switch reality target, node options, and WARP auto-update-IP hints from
inline extra text to label tooltips for a cleaner form layout.

internal/web/web.go

@@ -388,7 +388,7 @@ func (s *Server) cpuAlarmWanted() bool {
 		if threshold <= 0 {
 			return false
 		}
-		for _, e := range strings.Split(events, ",") {
+		for e := range strings.SplitSeq(events, ",") {
 			if strings.TrimSpace(e) == string(eventbus.EventCPUHigh) {
 				return true
 			}