Simplify public API to 3 functions

The public API is now:
  read_geotiff(source, ...)   # read anything: file, URL, cloud, VRT
  write_geotiff(data, path, ...)  # write any backend
  write_vrt(path, sources)    # generate VRT mosaic XML

read_geotiff auto-detects:
  - .vrt extension -> VRT reader
  - http:// / https:// -> COG range-request reader
  - s3:// / gs:// / az:// -> cloud via fsspec
  - gpu=True -> nvCOMP GPU decompression
  - chunks=N -> Dask lazy windowed reads

Removed from __all__: open_cog (deprecated wrapper),
read_vrt (called internally), read_geotiff_dask (use chunks=),
read_geotiff_gpu / write_geotiff_gpu (use gpu=True).

All these functions still exist for backwards compatibility but
are no longer the recommended entry points.

Author: brendancol

README.md

@@ -141,18 +141,22 @@ Native GeoTIFF and Cloud Optimized GeoTIFF reader/writer. No GDAL required.
 |:-----|:------------|:-----:|:----:|:--------:|:-------------:|:-----:|
 | [read_geotiff](xrspatial/geotiff/__init__.py) | Read GeoTIFF / COG / VRT | ✅️ | ✅️ | ✅️ | ✅️ | ✅️ |
 | [write_geotiff](xrspatial/geotiff/__init__.py) | Write DataArray as GeoTIFF / COG | ✅️ | ✅️ | ✅️ | ✅️ | ✅️ |
-| [read_vrt / write_vrt](xrspatial/geotiff/__init__.py) | Virtual Raster Table mosaic | ✅️ | ✅️ | ✅️ | ✅️ | |
+| [write_vrt](xrspatial/geotiff/__init__.py) | Generate VRT mosaic from GeoTIFFs | ✅️ | | | | |
 
 `read_geotiff` and `write_geotiff` auto-dispatch to the correct backend:
 
 ```python
-read_geotiff('dem.tif')                         # NumPy
-read_geotiff('dem.tif', chunks=512)             # Dask
-read_geotiff('dem.tif', gpu=True)               # CuPy (nvCOMP + GDS)
-read_geotiff('dem.tif', gpu=True, chunks=512)   # Dask + CuPy
-
-write_geotiff(cupy_array, 'out.tif')            # auto-detects GPU
-write_geotiff(data, 'out.tif', gpu=True)        # force GPU compress
+read_geotiff('dem.tif')                              # NumPy
+read_geotiff('dem.tif', chunks=512)                  # Dask
+read_geotiff('dem.tif', gpu=True)                    # CuPy (nvCOMP + GDS)
+read_geotiff('dem.tif', gpu=True, chunks=512)        # Dask + CuPy
+read_geotiff('https://example.com/cog.tif')          # HTTP COG
+read_geotiff('s3://bucket/dem.tif')                  # Cloud (S3/GCS/Azure)
+read_geotiff('mosaic.vrt')                           # VRT mosaic (auto-detected)
+
+write_geotiff(cupy_array, 'out.tif')                 # auto-detects GPU
+write_geotiff(data, 'out.tif', gpu=True)             # force GPU compress
+write_vrt('mosaic.vrt', ['tile1.tif', 'tile2.tif'])  # generate VRT
 ```
 
 **Compression codecs:** Deflate, LZW (Numba JIT), ZSTD, PackBits, JPEG (Pillow), uncompressed

xrspatial/geotiff/__init__.py

@@ -20,8 +20,7 @@
 from ._reader import read_to_array
 from ._writer import write
 
-__all__ = ['read_geotiff', 'write_geotiff', 'open_cog', 'read_geotiff_dask',
-           'read_vrt', 'write_vrt', 'read_geotiff_gpu', 'write_geotiff_gpu']
+__all__ = ['read_geotiff', 'write_geotiff', 'write_vrt']
 
 
 def _wkt_to_epsg(wkt_or_proj: str) -> int | None: