Stabilize auth flow and profile images

app/test/directory/contact_launcher_test.dart

@@ -0,0 +1,18 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:tdc114plus/src/core/actions/contact_launcher.dart';
+
+void main() {
+  test('buildCallUri normalizes separators and keeps country code', () {
+    final uri = buildCallUri('+82 10-1234-5678');
+
+    expect(uri, isNotNull);
+    expect(uri.toString(), 'tel:+821012345678');
+  });
+
+  test('buildSmsUri returns null for empty phone number', () {
+    final uri = buildSmsUri(' - ');
+
+    expect(uri, isNull);
+  });
+}