Goblin Build 116

Floonet scoped Nym exit on the money-path relay (dial a relay operator's
co-located exit over a MixnetStream, TLS end to end, no public DNS; anchor +
fallback, never pin-only), NIP-44 v3 gift wraps (G4), mix-DNS, localization,
GUI polish. Verified end to end: two wallets complete a real gift-wrapped Grin
payment over relay.goblin.st, finalized + posted on mainnet.

android/app/src/main/java/mw/gri/android/BackgroundService.java

@@ -23,6 +23,10 @@ public class BackgroundService extends Service {
     private boolean mStopped = false;
 
     private static final int NOTIFICATION_ID = 1;
+    // One-shot "payment received" notification, separate from the persistent
+    // sync notification above.
+    private static final int PAYMENT_NOTIFICATION_ID = 2;
+    private static final String PAYMENT_CHANNEL_ID = "PaymentReceived";
     private NotificationCompat.Builder mNotificationBuilder;
 
     private String mNotificationContentText = "";
@@ -189,6 +193,40 @@ public class BackgroundService extends Service {
         notificationManager.cancel(NOTIFICATION_ID);
     }
 
+    // Show a one-shot "payment received" notification (id=2), separate from
+    // the persistent sync notification (id=1). Called from native code via
+    // MainActivity when a payment slatepack is received over nostr, possibly
+    // while the app is backgrounded. Localization of the fixed strings is a
+    // follow-up (text is composed here at Java side).
+    public static void notifyPaymentReceived(Context context, String name, String amount) {
+        NotificationManager manager = context.getSystemService(NotificationManager.class);
+        if (manager == null) {
+            return;
+        }
+        // High-importance channel so the notification pops with sound + vibration.
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            NotificationChannel channel = new NotificationChannel(
+                    PAYMENT_CHANNEL_ID, "Payments", NotificationManager.IMPORTANCE_HIGH
+            );
+            manager.createNotificationChannel(channel);
+        }
+        Intent i = context.getPackageManager().getLaunchIntentForPackage(context.getPackageName());
+        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, i, PendingIntent.FLAG_IMMUTABLE);
+        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, PAYMENT_CHANNEL_ID)
+                .setContentTitle("Payment received")
+                .setContentText(name + " paid " + amount + " ツ")
+                .setSmallIcon(R.drawable.ic_stat_name)
+                .setPriority(NotificationCompat.PRIORITY_HIGH)
+                .setAutoCancel(true)
+                .setDefaults(NotificationCompat.DEFAULT_ALL)
+                .setContentIntent(pendingIntent);
+        try {
+            manager.notify(PAYMENT_NOTIFICATION_ID, builder.build());
+        } catch (SecurityException e) {
+            // POST_NOTIFICATIONS not granted: skip the notification, never the payment.
+        }
+    }
+
     // Start the service.
     public static void start(Context c) {
         if (!isServiceRunning(c)) {

android/app/src/main/java/mw/gri/android/MainActivity.java

@@ -421,6 +421,12 @@ public class MainActivity extends GameActivity {
     // Notify native code to stop activity (e.g. node) if app was terminated from recent apps.
     public native void onTermination();
 
+    // Called from native code to show a "payment received" notification
+    // (BackgroundService id=2) when a payment arrives over nostr.
+    public void notifyPaymentReceived(String name, String amount) {
+        BackgroundService.notifyPaymentReceived(this, name, amount);
+    }
+
     // Called from native code to set text into clipboard.
     public void copyText(String data) {
         ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
@@ -619,7 +625,12 @@ public class MainActivity extends GameActivity {
     // Called from native code to pick the file.
     public void pickFile() {
         Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
-        intent.setType("text/*");
+        // Permissive type: custom extensions like .backup have no registered
+        // MIME type, so any narrower filter greys them out in the picker and
+        // locks users out of restoring their identity. Content is validated
+        // on the native side after selection.
+        intent.setType("*/*");
+        intent.addCategory(Intent.CATEGORY_OPENABLE);
         try {
             mFilePickResult.launch(Intent.createChooser(intent, "Pick file"));
         } catch (android.content.ActivityNotFoundException ex) {