Replace in-tree pcodec with @eeholmes/zarrita-pcodec

[Copilot]

GridLook no longer carries its own pcodec decoder stack. pcodec is now registered through the external @eeholmes/zarrita-pcodec package while existing codec handling remains unchanged for non-pcodec datasets.

• Codec wiring

  • Register pcodec through zarrita’s global registry alongside the existing codec setup.
  • Keep registration eager so arrays can open without any local pcodec bootstrap.

• Dependency update

  • Add @eeholmes/zarrita-pcodec to the app dependencies.
  • Pin it to a fixed git SHA for reproducible installs.

• Removed in-tree implementation

  • Delete the local pcodec WASM loader and generated artifact.
  • Remove the Rust/WASM tooling used only to build the in-repo decoder.
  • Drop pcodec-specific registration code and related .gitignore entries.

• Behavior preserved

  • Existing codec infrastructure still loads.
  • pcodec-compressed Icechunk/Zarr data continues to resolve through the external package.

import * as zarr from "zarrita";
import { registerPCodec } from "@eeholmes/zarrita-pcodec";

registerPCodec(zarr.registry);