- Add escape_like() helper to escape % and _ wildcards in LIKE queries
- Update fail2ban_db_repo.get_history_page() to use escaping
- Update history_archive_repo.get_archived_history() to use escaping
- Add ESCAPE clause to all LIKE queries
- Add comprehensive unit tests for escape_like function
- Add integration tests for LIKE wildcard handling
- Document LIKE escaping best practices in Backend-Development.md
Fixes TASK-017: Prevent unintended LIKE matches when IP filter contains
special characters like underscore or percent sign.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
