Bugfix : nextDuration not cleared after consumption in Solfa.kt

composeApp/src/commonMain/kotlin/mg/dot/feufaro/solfa/Solfa.kt

@@ -587,6 +587,7 @@ class Solfa(val sharedScreenModel: SharedScreenModel, private val fileRepository
                 '@' -> {
                     if (lastNoteString == "z") {
                         midiDuration += nextDuration
+                        nextDuration = 0
                     } else {
                         pushMidi()
                     }