potentiomap 0.2.0

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.

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.

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

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.

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.

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

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

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.

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.

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.