perf(copc): decode TypeScript LAZ into Arrow attributes

[ibgreen]

Goals

• Route TypeScript COPC tile rendering through the optimized selective LAZ decoder.
• Remove avoidable point-data copies and traversals without changing the public COPC API or general raw-record access.

Changes

• Decode valid COPC PDRF 6-8 node chunks directly into typed position and RGB arrays.
• Eliminate the intermediate raw LAS record buffer, batch concatenation, Las.View, and second getter-based point traversal from loadTileContent.
• Preserve the raw-record path for schema inspection and arbitrary-dimension access.
• Avoid a redundant per-point projection array clone where the projection loop already owns its temporary coordinate.
• Compare every root-node Arrow position and color row against the laz-perf backend.
• Document direct Arrow attribute output in the LAS/LAZ capability table.

Performance

Local single-thread profiling on the 66,272-point ellipsoid.copc.laz root node measured median end-to-end TypeScript tile throughput increasing from approximately 0.79M to 1.16M points/s, about 46% faster.

Supporting PDRF 7 profiling measured selective typed-array decode at approximately 2.31M points/s, compared with 1.56M points/s for complete raw-record decode. The remaining complete-path CPU cost is split primarily between LAZ arithmetic decoding and proj4 transformation.

Validation

• yarn install
• yarn lint fix
• yarn build
• yarn test-node: 403 files passed, 1,917 tests passed
• yarn test-headless: 406 files passed, 1,882 tests passed