Add lightweight native decompression

[ibgreen-openai]

Goals

• Let async consumers use runtime DecompressionStream support without eagerly importing codec fallbacks.
• Preserve deterministic codec-backed compression classes and existing synchronous behavior.

Changes

• Added the zero-dependency @loaders.gl/compression/native-decompression subpath for gzip, deflate, raw deflate, Brotli, and forward-compatible Zstandard probing.
• Added codec-specific subpaths so fallback implementations can be dynamically imported without pulling every codec into one chunk.
• Made Parquet gzip/Brotli/Zstandard and SPZ Zstandard decompression native-first, with registered Brotli/Zstandard modules taking precedence and codec fallbacks loaded only when needed.
• Removed automatic optional installation of Brotli, LZ4, and Zstandard codec packages from @loaders.gl/compression; Parquet no longer installs Brotli or zstd-codec as runtime dependencies.
• Kept GZipCompression, DeflateCompression, BrotliCompression, and ZstdCompression codec-backed and deterministic; compression and sync APIs retain their behavior.
• Added real-runtime atomic and batched tests for every native format when supported, plus mocked unsupported, failure, Parquet fallback/module-override, and SPZ native/module-override coverage.
• Documented the lightweight entrypoint, lazy fallback behavior, future-facing Zstandard support, and v5 release note.

Validation

• corepack yarn
• corepack yarn build
• corepack yarn test-node
• corepack yarn lint fix
• cd website; corepack yarn; corepack yarn build
• Bundled the native entrypoint and Parquet path with esbuild splitting: the native entrypoint is ~2.8 KB with no imports, and pako is absent from the initial Parquet chunk.