[Tingliangstu]

GPUMD XYZ previously ignored unwrapped_position, and LAMMPS text dumps preferred x y z even when xu yu zu were available. Prefer explicit unwrapped coordinates in both readers and unwrapped_coordinates in NetCDF; retain the original-coordinate fallback when those fields are absent. Reject incomplete unwrapped fields.

Report the coordinate choice only when an explicit unwrapped field is used:

        Coordinates             : unwrapped (unwrapped_position from GPUMD)
        Coordinates             : unwrapped (xu yu zu from LAMMPS)

Each run prints only its applicable line. Update the manual with GPUMD/LAMMPS output commands and the same selection rules.

The text-cache schema advances to version 3 so previous conversions are rebuilt once. SED computation and normalization are unchanged; there is no new input parameter or on-the-fly unwrapping.

Validation:

• WSL pysed: 42 focused tests passed, including 106 subtests, with CPU threads limited to one. The optional CuPy test was excluded.
• Verified ordinary/unwrapped console output with tiny GPUMD/LAMMPS fixtures.
• Strict Sphinx HTML build passed without warnings; checked the four changed pages.
• An earlier Windows run encountered the existing CRLF progress-byte-count test failure; confirmed it also occurs with the unchanged base reader. No Windows-specific fix is included.

Only source, documentation, and necessary tests are included.