feat(profile): implement user-initiated GDPR-compliant profile deletion

- Add DELETE /users/me endpoint with cascading data removal
- Implement frontend confirmation dialog and deletion flow
- Add audit logging for deletion requests
- Update localization files for new UI strings
- Add scheduled cleanup service for AI traces
- Document GDPR compliance in technical specification

BREAKING CHANGE: Users can now permanently delete their profiles and associated data

flutter/pubspec.yaml

@@ -21,6 +21,7 @@ dependencies:
   shared_preferences: ^2.5.5
   file_picker: ^11.0.2
   web: ^1.1.1
+  intl_utils: ^2.8.14
 
 dev_dependencies:
   flutter_test: