Add quantize and cull unused blocks

[alexchuber]

Summary

• Add core-only QuantizeBlock and CullUnusedBlock as thin wrappers around glTF-Transform's default quantize() and prune() behavior.
• Keep quantization extension registration in QuantizeBlock and export both blocks.
• Add only their block-list definitions and one pipeline-result integration test per block. No CLI, dependency, or tuning-option changes.

Validation

Both new integration tests, the full existing test suite (179 tests), changed-file ESLint, typecheck, and the core build passed. The build emitted the existing TypeScript/API Extractor version warning.

Code review

Findings

No findings. No follow-up code changes were needed.

Reviewed immutable range eae03b45471c18361b1e8850ebaf0aa855490fa9..358803fd5291658f7221886647c4864418a154bb using the code-review skill. All reviewers used GPT-5.6 Sol with High reasoning effort as requested.

Coverage

Reviewer	Result	Notes
Standards	No findings	Repository conventions and explicit scope constraints
Spec	No findings	Direct user requirements and confirmed choices
Bundle size	No findings	Tree-shaken output
Synchronization	No findings	Execution and scheduling
Time complexity	No findings	Transform wrappers
Memory	No findings	Resource lifetime and allocation
JavaScript	No findings	Self-review
Comments	No findings	Self-review

Summary: 0 findings — 0 critical, 0 high, 0 medium, 0 low. Coverage: 8/8 selected reviewers completed.