refactor: prepare first version release

.gitignore

@@ -24,3 +24,8 @@ node_modules/
 
 # Firebase config (App Distribution) — per-developer, not tracked (see google-services.example.json)
 androidApp/google-services.json
+
+# Android signing — must NOT be checked into Version Control
+keystore.properties
+*.jks
+*.keystore