fix(autosave): morph instead of replace to preserve controller instances

app/views/champs/piece_justificative/show.turbo_stream.haml

@@ -1,5 +1,5 @@
 = fields_for @champ.input_name, @champ do |form|
-  = turbo_stream.replace @champ.input_group_id, partial: "shared/dossiers/editable_champs/editable_champ", locals: { champ: @champ, form: form }
+  = turbo_stream.morph @champ.input_group_id, partial: "shared/dossiers/editable_champs/editable_champ", locals: { champ: @champ, form: form }
 
 - if @champ.piece_justificative_file.attached?
   - attachment = @champ.piece_justificative_file.attachment

spec/controllers/champs/piece_justificative_controller_spec.rb

@@ -29,7 +29,7 @@ describe Champs::PieceJustificativeController, type: :controller do
       it 'renders the attachment template as Javascript' do
         subject
         expect(response.status).to eq(200)
-        expect(response.body).to include("action=\"replace\" target=\"#{champ.input_group_id}\"")
+        expect(response.body).to include(""action":"morph","target":"#{champ.input_group_id}"")
       end
 
       it 'updates dossier.last_champ_updated_at' do