feat(apps): update UI screens and shared components

- Update home screen with new composer and interactions
- Update settings screens with new profile flow
- Update calendar share dialog
- Update contacts screen
- Add new shared widgets: confirm_sheet, phone_prefix_selector
- Add new formatters: phone_display_formatter
- Update tests for modified components

apps/test/shared/utils/phone_display_formatter_test.dart

@@ -0,0 +1,30 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:social_app/shared/utils/phone_display_formatter.dart';
+
+void main() {
+  group('formatPhoneForDisplay', () {
+    test('formats +86 numbers as local masked style', () {
+      final formatted = formatPhoneForDisplay('+8613812345678');
+
+      expect(formatted, '138****5678');
+    });
+
+    test('keeps international country code while masking middle part', () {
+      final formatted = formatPhoneForDisplay('+14155552671');
+
+      expect(formatted, '+1 ****2671');
+    });
+
+    test('normalizes separators before formatting', () {
+      final formatted = formatPhoneForDisplay('(+86) 138-1234-5678');
+
+      expect(formatted, '138****5678');
+    });
+
+    test('prefers longer country code in fallback detection', () {
+      final formatted = formatPhoneForDisplay('+33612345678');
+
+      expect(formatted, '+33 ****5678');
+    });
+  });
+}