Question juridique clé
Whether the cantonal court could replace old-law detention with a therapeutic measure rather than convert it to new-law detention.
Solution extraite
The prosecutor's request to continue detention was disregarded because it would worsen the appellant's position and a reformatio in peius is not allowed in this posture.
Motifs extraits
In the appeal proceedings, the court is bound by the appellant's requests; the respondent may only seek dismissal, not a worse outcome for the appellant, absent its own timely appeal.