Add ability to compare/sort/merge items using a sortby config

crates/core/CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Added
 
+- Add `stac::sort` module for sorting items and streams of items based on a JSON configuration ([#856](https://github.com/stac-utils/rustac/pull/856))
 - Add `max_row_group_size` parameter to `geoparquet::WriterBuilder` with default value of `150_000` ([#846](https://github.com/stac-utils/rustac/pull/846))
 
 ## [0.14.0] - 2025-11-14

crates/core/Cargo.toml

@@ -48,6 +48,8 @@ serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true, features = ["preserve_order"] }
 stac-derive.workspace = true
 thiserror.workspace = true
+stream-kmerge = "0.2.0"
+futures = { workspace = true }
 tracing.workspace = true
 url = { workspace = true, features = ["serde"] }
 wkb = { workspace = true, optional = true }

crates/core/src/lib.rs

@@ -123,6 +123,8 @@ pub mod link;
 mod migrate;
 pub mod mime;
 mod ndjson;
+/// Sort STAC items.
+pub mod sort;
 mod statistics;
 mod value;
 mod version;