v1.0.0

First release:

• Add the first Perl SplatHash encoder and decoder.
• Add raw RGBA parity vectors generated from the Go reference implementation.
• Add image-file encoding through Imager.
• Add a command-line tool that writes a decoded PNG preview and prints the hash.
• Add a Perl-vs-Go benchmark script for upstream SplatHash assets.
• Add the pinned upstream assets and publish per-image benchmark results.
• Optimize sampling, matching pursuit, and decoding while preserving parity.
• Add the project MIT licence and preserve the upstream third-party notice.
• Classify licence validation as an author test.
• Document AI-assisted development provenance and human review scope.