Changes in version 0.2.0 (2026-07-18)                  

Observation preparation and quality checks

  - Added ps_check_observations(), ps_select_event(), and
    ps_screen_groups() with record-level issue, exclusion, ambiguity,
    and grouping manifests.

Validation and tuning

  - Added deterministic leave-one-out, random-fold, spatial-block,
    leave-cluster-out, user-fold, and independent validation through
    ps_validate().
  - Added design-specific method comparison, diagnostic plotting,
    exhaustive or reproducibly sampled candidate tuning, and optional
    nested validation.

Variograms, anisotropy, and trends

  - Added empirical and directional variograms, independent
    candidate-model fitting, exploratory anisotropy, explicit variogram
    models, neighborhoods, anisotropy, trends, and raster or table
    covariates for kriging.

Support and uncertainty

  - Added compatible-surface ensembles and method-disagreement products.
  - Added retained kriging variance, conditional Gaussian simulation,
    supported TPS standard error, resampling sensitivity, and pointwise
    contour bands with explicit terminology and assumptions.
  - Prediction-support products retain training-hull,
    observation-distance, mask, and finite-prediction information, and
    modeled contours can be split by user-defined support criteria
    without calling those classes confidence.

Surface and event comparisons

  - Added aligned surface comparisons, paired-event head change, and
    numeric or raster vertical hydraulic gradients with explicit sign
    conventions.
  - Structured interpolation and contour results inventory diagnostics,
    conditions, requested methods or levels, and nonfinite outputs.

Monitoring-network analysis

  - Added conditional leave-one-well influence, reproducible network
    thinning, constrained sequential candidate ranking, and explicit
    parameter/grid sensitivity scenarios.

Profiles, cross-sections, and depth products

  - Added water-table or potentiometric depth surfaces, sampled surface
    profiles, and plot-ready cross-sections with well offsets and screen
    elevations.

GIS and reporting

  - Added validated open QML/SLD style export and offline HTML/DOCX
    technical reports from a package-owned template.
  - Hydraulic-gradient arrows retain endpoint support checks and the
    explicit endpoint_action = "none" legacy geometry option.

Documentation

  - Added small deterministic fixtures, expanded function examples,
    integrated vignettes, website articles, scientific due diligence,
    and release audits.
  - Rebuilt the hydrogeologist-facing README, package help, reference
    index, and Bootstrap 5 website configuration, with guidance for
    on-disk rasters and larger prediction grids.

Compatibility

  - Existing public functions remain exported, and ps_interpolate()
    continues to return a named list of SpatRaster objects by default.
  - Structured interpolation results now also retain exact template and
    method-fit objects needed by validation and model-conditional
    uncertainty.
  - ps_contours() still returns a SpatVector by default; structured
    interpolation and contour results remain opt-in.
  - Existing public names and valid positional calls remain available,
    requested interpolation methods are not silently replaced, and
    universal kriging keeps the documented uk_coordinate_scaling =
    "none" compatibility option.