feat(collections): pf-4401 worker threads

[cdcabrera]

What is it?

• feat(collections): pf-4401 worker threads
  • collections, apply proxy for heavy tasks via workers
  • server.workerPool, pooled worker threads, queue cap, shutdown
  • server.workerRunner, module exec with AsyncLocalStorage isolation, parentPort keep-alive
  • server.workerEntry, dedicated worker entry for spawn/import resolution
  • server, wire worker pool into request flow used by collections
  • tools, new dedicated export for user facing tools, avoid worker conflicts
  • docs, public API/deprecations, example import paths for dedicated user facing tools
  • tests, add coverage for worker pool/runner and refresh snapshots
  • jest.setupTests, worker mock, include setup, env updates
  • package, add #workerEntry import alias for worker script, export for user facing tools

Notes

• supersedes feat(collections): pf-4401 process spawn, ipc #273 with worker-threads for hybrid collections (collections requiring parallel behavior) vs a child-process (fully isolated)
• moving to worker-threads relates easier context for settings around global options and sessions.
• the child-process implementation while feasible and functional was ... "intense". we'll reserve child-process for collections-as-plugins in the future
• we ended up having to adjust how threads are spooled up because it conflicted with the centralized export for tools-as-plugins. as an extra safety measure to avoid spooling workers when someone just wanted to write a tool-as-plugin we separated out the tools export for users and deprecated the previous central export, planned removal for 3.0.0

Updates issue/story

related to #272 #241 #242 and pf-4401 pf-4402
supersedes #273