- Catch PermissionError/OSError in file operations (not just FileNotFoundError)
- Refactor _dedup_netntlm_by_username to two-pass streaming (memory safe)
- Handle CRLF line endings in filter and dedup functions
- Add KeyboardInterrupt handling with temp file cleanup during preprocessing
- Track .filtered/.dedup temp files for cleanup on interruption
- Add CRLF line ending tests for both filter and dedup
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>