fix(audit): stop default read logging and dedupe dashboard timeline

- skip read audit logging unless a path is explicitly allowlisted
- exclude audit-facing endpoints from backend audit collection
- remove duplicate auth timeline fetch logic from dashboard screen
- add regression tests for default GET skip and dashboard timeline dedup

Co-Authored-By: First Fluke <our.first.fluke@gmail.com>

userfront/test/dashboard_timeline_dedup_test.dart

@@ -0,0 +1,16 @@
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('대시보드 화면은 auth timeline fetch 구현을 직접 가지지 않는다', () async {
+    final screenFile = File(
+      'lib/features/dashboard/presentation/dashboard_screen.dart',
+    );
+    final source = await screenFile.readAsString();
+
+    expect(source.contains('_fetchAuditLogs('), isFalse);
+    expect(source.contains('_loadAuditLogs('), isFalse);
+    expect(source.contains('/api/v1/audit/auth/timeline'), isFalse);
+  });
+}