Pcodec

* New format version (3)
* API breaking changes
* All metadata types (e.g. `ChunkMeta`) now live in the `pco::metadata::` module.
* Metadata and `ChunkCompressor` types are no longer generic to latent type. Instead they contain dynamically-typed values, leveraging the `dtype_dispatch` crate.
* Renamed `NumberLike => Number`.
* Delta encoding is now configured via `DeltaSpec` enum of an `Option<usize>`, and similarly `ChunkMeta` contains a `DeltaEncoding` enum.
* API additions
* Added `simple_compress_into` function.
* Added a `Lookback` delta encoding that improves compression ratio on some types of data.
* Improvements
* Improved bin optimization speed on Windows slightly.
* Improved `FloatQuant` auto mode heuristics, improving the size/speed tradeoff.
* Reduced binary size via fewer unnecessary specializations.

Python_v0.3.1
* Added `DeltaSpec.try_lookback()` configuration.
* Upgraded Rust implementation to 0.4.0.

Python_v0.3.0.2
* Published Python 3.13 wheels for the first time (assuming this works).
* Replaced delta_encoding_order optional int configuration with delta_spec class.

Reduced minimum version requirement for `half` crate.

* New format version (2)
* API breaking changes
* Replaced `FloatMultSpec` and `IntMultSpec` with `mode_spec: ModeSpec` in `ChunkConfig`.
* Removed `auto_delta_encoding_order` function.
* API additions
* Added support for 16-bit data types.
* Added `LatentDescriber` API, accessible by `NumberLike::get_latent_describer`.
* Improvements
* Added `FloatQuant` mode and automatic detection for it, improving compression ratio on quantized float data.
* Increased compression speed for high compression levels slightly.

Python_v0.2.0
* Added support for 16-bit types.
* Replaced separate `int_mult_spec` and `float_mult_spec` configs with`mode_spec: ModeSpec`.
* Upgraded Rust implementation from 0.2.5 to 0.3.0.

Python_v0.1.1
Upgraded Rust implementation from 0.1.3 to 0.2.5.

Fixed a bug in v0.2.4 that caused a panic during histogram computation under certain conditions.

* Made int mult detection more statistically principled, reducing false positive rate.
* Improved compression speed by sorting only partially to compute the histogram. This is 10-50% faster at default compression level, but 300+% faster at low compression levels.
* Yanked because a bug (causing a panic) was discovered right after publishing.

No real changes, but bumped `better_io` version to 0.1.0.