fix: MIDI keyboard preview silent after transport STOP — live flag bypass guard (V8)

src-tauri/src/lib.rs

@@ -667,11 +667,12 @@ fn push_midi_event(
     data2: u8,
     data3: u8,
     sample_offset: u32,
+    live: bool,
 ) -> Result<(), String> {
     let state = app.state::<ShmState>();
     let guard = state.0.lock().map_err(|e| e.to_string())?;
     let shm = guard.as_ref().ok_or("bridge shm unavailable")?;
-    shm.push_midi(command, channel, pitch, velocity, data2, data3, sample_offset)
+    shm.push_midi(command, channel, pitch, velocity, data2, data3, sample_offset, live as u8)
         .then_some(())
         .ok_or_else(|| "midi queue full".to_string())
 }

src-tauri/src/shm.rs

@@ -34,7 +34,7 @@ pub struct MidiEventIPC {
     pub velocity: u8,
     pub data2: u8, // CC value / program / PB LSB
     pub data3: u8, // PB MSB (0xE only)
-    pub reserved: [u8; 2],
+    pub reserved: [u8; 2], // reserved[0]: live flag (1=live input, bypass transportStopped guard); reserved[1]: 0
     pub sample_offset: u32,
 }
 
@@ -112,7 +112,7 @@ impl Shm {
         unsafe { &mut *self.view }
     }
 
-    pub fn push_midi(&self, cmd: u8, channel: u8, pitch: u8, velocity: u8, data2: u8, data3: u8, sample_offset: u32) -> bool {
+    pub fn push_midi(&self, cmd: u8, channel: u8, pitch: u8, velocity: u8, data2: u8, data3: u8, sample_offset: u32, live: u8) -> bool {
         let ipc = self.ipc();
         if ipc.midi_queue_count as usize >= MIDI_QUEUE_CAP {
             return false;
@@ -125,7 +125,7 @@ impl Shm {
             velocity,
             data2,
             data3,
-            reserved: [0u8; 2],
+            reserved: [live, 0u8],
             sample_offset,
         };
         ipc.midi_queue_count += 1;