Home: add Discard with confirm to in-progress recording card

- RecordingStatusCard: Pause/Resume + Finish + Discard (red)
- Discard shows confirm dialog ('Delete current recording?')
  then discards temp via ACTION_DELETE; Cancel keeps recording

android/app/src/main/java/com/shonar/ui/home/HomeScreen.kt

@@ -167,6 +167,7 @@ fun HomeScreen(
                     onPause = vm::pause,
                     onResume = vm::resume,
                     onStop = vm::stop,
+                    onDiscard = vm::discard,
                 )
             }
             if (recordings.isNotEmpty()) {
@@ -213,7 +214,9 @@ private fun RecordingStatusCard(
     onPause: () -> Unit,
     onResume: () -> Unit,
     onStop: () -> Unit,
+    onDiscard: () -> Unit,
 ) {
+    var confirmDiscard by remember { mutableStateOf(false) }
     Card(Modifier.fillMaxWidth()) {
         Column(Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(8.dp)) {
             Text(
@@ -226,10 +229,28 @@ private fun RecordingStatusCard(
                     Text(if (state.phase == com.shonar.recording.RecordingSnapshot.Phase.PAUSED) "Resume" else "Pause")
                 }
                 TextButton(onClick = onStop) { Text("Finish") }
+                TextButton(onClick = { confirmDiscard = true }) {
+                    Text("Discard", color = MaterialTheme.colorScheme.error)
                 }
             }
         }
     }
+    if (confirmDiscard) {
+        AlertDialog(
+            onDismissRequest = { confirmDiscard = false },
+            title = { Text("Delete current recording?") },
+            text = { Text("This throws away the in-progress take. It can't be undone.") },
+            confirmButton = {
+                TextButton(
+                    onClick = { confirmDiscard = false; onDiscard() },
+                ) { Text("Delete", color = MaterialTheme.colorScheme.error) }
+            },
+            dismissButton = {
+                TextButton(onClick = { confirmDiscard = false }) { Text("Cancel") }
+            },
+        )
+    }
+}
 
 @Composable
 private fun RecordingRow(