Rust implementation of GA4GH Refget sequence collection functions

This module provides functions managing and retrieving sequences from a sequence collection.

Module Structure

The library is organized into two main parts:

Core (WASM-compatible)

The digest module contains all WASM-compatible code:

• digest::algorithms - Hash functions (sha512t24u, md5, canonicalize_json)
• digest::alphabet - Sequence alphabets and encoding tables
• digest::encoder - Sequence bit-packing
• digest::types - Core data structures (SequenceRecord, SequenceCollection)
• digest::fasta - Bytes-based FASTA parsing
• digest::stream - Streaming FASTA hasher for chunk-by-chunk processing

Filesystem (requires filesystem feature)

• fasta - File-based FASTA parsing (wraps digest::fasta with file I/O)
• collection - Extended SequenceCollection with filesystem operations
• store - RefgetStore for persistent sequence storage

Feature Flags

• filesystem (default): Enables file-based operations
• Without filesystem: Only WASM-compatible code in digest module