feat(ts): initial toMultiscales

[thewtex]

Functionality required for test_multiscales_metadata_test.ts

[Copilot]

Pull Request Overview

This PR implements the initial toMultiscales functionality for TypeScript, adding support for metadata tracking of downsampling methods in the OME-Zarr specification. The implementation provides a simplified version focused on metadata handling rather than actual downsampling operations.

Key changes:

• Addition of MethodMetadata interface and schema to track downsampling method information (description, package, version)
• Implementation of toNgffImage and toMultiscales functions for creating NgffImage and Multiscales objects
• Integration of method metadata into the zarr serialization pipeline

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
ts/test/test_multiscales_metadata_test.ts	Comprehensive test suite verifying metadata field population, serialization, and round-trip operations
ts/test/hcs_test.ts	Updated import statement to use short-form @std/assert
ts/src/utils/method_metadata.ts	New utility for generating method metadata based on downsampling method type
ts/src/types/zarr_metadata.ts	Added MethodMetadata interface and optional metadata/type fields to Metadata interface
ts/src/schemas/zarr_metadata.ts	Added Zod schema validation for MethodMetadata and updated MetadataSchema
ts/src/mod.ts	Exported new utility functions and types
ts/src/io/to_ngff_zarr.ts	Updated to serialize optional metadata and type fields to zarr attributes
ts/src/io/to_multiscales.ts	New implementation of toNgffImage and toMultiscales functions