feat(experimental): add GPU-native hierarchical trace manipulation

[ibgreen-openai]

Goals

• Move dynamic hierarchical trace manipulation, filtering, dependency focus, and layout onto the GPU.
• Provide a realistic, reusable foundation for hierarchical process/thread and linked-span exploration without CPU readback in the rendering hot path.

Architecture

Changes

• Add and export four reusable GPU command-graph primitives: GPUMask, GPUGraphTraversal, GPUHierarchyLayout, and GPUAncestorProjection.
• Support stable mask composition over GPU data and chunk-preserving GPU vectors; bounded, cycle-safe forward, reverse, and bidirectional CSR traversal; GPU-scanned process/thread expansion; and nearest-visible hidden-parent projection.
• Replace the trace example with deterministic canonical span records, stable source identities, process/thread hierarchies, sparse cross-process dependencies, forward/reverse adjacency, classification, and topology flags.
• Add GPU-native status, duration, runtime, error, and topology filtering; interactive process/thread collapse; focused multi-hop linked-span selection; projected dependency rendering; atomic picking; activity aggregation; and fixed indirect draws.
• Add real Chromium/WebGPU primitive and interactive-viewer integration tests, deterministic Node tests, four API reference pages, navigation, and updated example documentation.

Verification

• yarn lint fix
• yarn lint
• yarn build
• yarn workspace luma.gl-examples-experimental-gpu-trace-viewer build
• yarn website:build
• (cd website && yarn build)
• yarn test-headless modules/experimental/test/gpu-primitives/gpu-trace-manipulation.spec.ts test/examples/gpu-trace-viewer.spec.ts
• yarn test-node test/examples/gpu-trace-viewer.node.spec.ts
• yarn website-debug --example experimental/gpu-trace-viewer --backend webgpu-core --headless: live WebGPU adapter, successful viewer rendering, and zero console, page, or request errors.
• The repository pre-commit hook independently passed formatting/lint and the full Node suite: 181 passed, 2 skipped.

Existing full-suite limitation

yarn test passes all 181 Node tests and 1,283 browser tests, but reports one existing failure in modules/arrow-layers/test/layers/arrow-layers.spec.ts: Arrow polygon and text layers render storage-backed WebGPU models expects a drawable storage-backed polygon instance. The identical failure was independently reproduced against the original checkout, with no GPU trace changes, and is unrelated to this PR.