comprehensive update

[walkerbdev]

• Restructured flat scripts into a datastore_statistics/ package
• Added CLI (cli.py), file readers (readers.py), image quality metrics (stats.py), HTML reports (report.py), and utilities (utils.py)
• Added pyproject.toml, pre-commit hooks, and updated .gitignore
• Added comprehensive test suite with shared fixtures
• Expanded README with installation, usage, and metrics docs
• Multimetric outlier detection (compute outlier detection for multiple metrics vs only single metric)
  New metrics:
• Spatial: n_slices, matrix_x/y, voxel_x/y/z, fov_x/y/z
• Center of mass: com_x/y/z (in mm when voxel spacing is available)
• Image quality: efc (Entropy Focus Criterion) and fber (Foreground-Background Energy Ratio)
• Masking: foreground_pct, auto_threshold (Otsu)

[hamshkhawar]

@walkerbdev It looks good. Few suggestion mainly adding type annotations for input prams and return values