All necessary imports and test infrastructure are already in place:
- Standard library imports (fs, path, process)
- pdftract CLI imports (exit codes)
- pdftract Core imports (diagnostics, decryption errors)
- Test helpers (pdftract_bin, encrypted_fixture, assertion functions)
- Test modules (unsupported_handlers, exit_codes, password_handling, consistency)
File compiles successfully and all imports match actual crate structure.
Infrastructure was implemented in previous commit as part of bf-5for4.
Closes bf-2nl4x
