perf: series of perf optimisations

[matthew2564]

Description

• Reduced overhead in hot transformation paths
• Added/expanded caching in metadata/property resolution paths
• Added perf benchmarks (test/perf-bench.ts, test/perf-matrix.ts)
• Updated lock/dependency setup to resolve tooling compatibility so CI/lint/tests run cleanly

Checklist

• the pull request title describes what this PR does (not a vague title like Update index.md)

• the pull request targets the default branch of the repository (develop)

• the code follows the established code style of the repository

  • npm run prettier:check passes
  • npm run lint:check passes

• tests are added for the changes I made (if any source code was modified)

• documentation added or updated

• I have run the project locally and verified that there are no errors

  Perf Snapshot

  Benchmark	Config	Before (ms)	After (ms)	Delta (ms)	Improvement
  test/perf-bench.ts	CT_BENCH_ITERS=40, CT_BENCH_SIZE=1200	432.70	152.24 (5-run avg)	-280.46	64.82% faster (~2.84x)

  Current run samples (ms)
  152.18
  149.57
  154.11
  151.79
  153.54