[Tingliangstu]

What changed

• Add eigenvector_file for Phonopy projection with the existing positive spatial phase, normalization, and CPU/GPU q batching.
• Write plain-text <prefix>.SED_mode_N files under mode-resoved-SED/, sharing the existing axes.
• Add mode_index and fit_all_modes for plotting/fitting, with separate text fit results and documentation.

What this improves

• Resolves individual reference modes while retaining ordinary total/partial spectra. All modes are checked against the independently accumulated total before output.
• Streams YAML by q point; checks q coverage, site mapping/periodic images, orientation, and eigenvector completeness.

Validation

• Ba_Ga_Ge: 432,000 atoms, first 64 frames, 2 blocks, 66 path entries, 162 modes. Text sum error relative to peak total intensity: 7.984e-15; maximum pointwise relative error: 1.173e-14. Independent total-only run agrees exactly. This checks completeness, not converged lifetimes.
• 13 new tests include complex single-mode isolation, reordered atoms/periodic images, CPU workers, GPU dispatch via a NumPy adapter, text roundtrip, and fitting.
• Suite: 159 passed, 2 skipped; 2 Windows failures were reproduced on the unmodified base and deselected (CRLF byte offsets and native worker thread limits).
• Actual CUDA hardware validation remains outstanding (CuPy unavailable). The 0.01 amu Ge mass mismatch is reported; original masses and data are unchanged.

Targets the existing 3.0 architecture branch. Local data and validation outputs are not committed.