Changes in version 0.1.0.9001                      

New features

  - New vrtstack() is a single entry point with two construction paths
    that share one concat-axis resolver:
    
      - from-scratch (template = NULL) — the existing GeoTIFF/COG
        behaviour, stacking 2D sources into a single new 3D array.
      - template-extend (template = <vrt> or template = TRUE) — fleshes
        out a small "first-n" multidimensional VRT to a full file set,
        re-parameterising only the concat dimension and the per-array
        <Source> lists. Coordinate arrays, slab geometry, and per-array
        scale/offset/unit/attributes are carried through verbatim from
        the template.

  - New mdim_template_extend() performs the recipe rewrite as a pure
    xml2 tree operation (no GDAL required). It handles sources that
    themselves carry several arrays (e.g. OISST anom/err/ice/sst): data
    arrays are detected structurally as any <Array> owning a <Source>,
    and each array's SourceArray path and slab count/step are read from
    its first source rather than assumed from the array name. The concat
    axis position is taken from DimensionRef order, so it need not be
    axis 0.

  - New resolve_concat() turns a concat-axis spec (explicit vector,
    single-group regex over basenames, function of basename, or
    date-parsing inputs) into axis values, and is shared by both
    construction paths.

  - New mdim_mosaic_xml() builds the first-n recipe via gdal mdim mosaic
    through /vsimem/, so no template file need touch disk (requires
    gdalraster with the gdal_run algorithm interface).

Minor improvements and fixes

  - Filename extraction now uses stringr::str_match() instead of
    regmatches()/regexec(), which silently dropped non-matches and
    misaligned rows against files.

  - VRT construction and editing now go through xml2 rather than string
    assembly, removing the hand-rolled XML escaping.

  - mdim_template_extend() rejects Date/POSIXct concat_values with a
    clear message: coordinate values must already be in the array's
    declared units (e.g. days-since-epoch). Encode them first via
    resolve_concat(origin=, unit=) or read them from the source files.

vrtstack (0.1.0)

  - gdal_mdim_stack() and the convenience wrappers vrt_time_stack(),
    vrt_depth_stack(), and vrt_regular_stack() for stacking 2D rasters
    into a multidimensional VRT along a new dimension, with regular-axis
    detection, filename-based dimension values, and /vsicurl/ support.