Roadmap

Required:
- [x] Switch from `--worker` flag to another `addprocs` setup mechanism (#2)

Enhancements (speculative, these are up for discussion):
- [ ] `@always_everywhere` and other pre-loading support
- [x] Worker state change notifications (worker added, worker exiting, etc.) (https://github.com/JuliaParallel/DistributedNext.jl/pull/17)
- [ ] Experiment with multi-cluster setups
- [ ] Type-stable interfaces and serialization
- [ ] Observability tools

Bug Fixes:
- [x] Fix/improve thread safety (#4)
- [x] Fix RemoteChannel `isempty` (#3)

This is a broad roadmap rather than a scoped implementation issue, and it names no files, tests, or entry points. Start by reviewing the unchecked items and the referenced issues and pull request, then identify one item with an agreed scope. Done is not defined for the roadmap as a whole.

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