BREAKING: search() now returns SearchResult instead of bare GeoDataFrame.
Access the raw GeoDataFrame via .tiles or .to_geodataframe().

- SearchResult with chainable .download(), .mosaic(), .preview(), .map()
- .estimate_size(), .to_geoparquet(), .to_geojson(), .compare()
- Enhanced search: intersects, CQL2 filter, sortby, ids, fields
- Point + buffer_miles for circular area searches
- Concurrent downloads with ThreadPoolExecutor (configurable workers)
- Resumable downloads with .part file protocol and HTTP Range headers
- Cloud-native COPC reads via laspy.CopcReader (spatial + LOD queries)
- CLI estimate subcommand for download size predictions
- Community health docs: governance, maintainers, responsible use, privacy