Ad and purchases enabled (still need actual testing)

.gitignore

@@ -43,3 +43,10 @@ app.*.map.json
 /android/app/debug
 /android/app/profile
 /android/app/release
+
+# Release signing credentials — never commit. The keystore itself lives
+# outside the repo entirely (~/.android/), but the passwords in here are
+# sensitive regardless.
+/android/key.properties
+*.jks
+*.keystore