New `tractor.devx._proctitle` mod sets each
sub-actor's `argv[0]` (and kernel `comm`) to
`tractor[<aid.reprol()>]` — e.g.
`tractor[doggy@1027301b]` — so `ps`/`top`/`htop`
and `acli.pytree`/reaper tooling can identify
actors at a glance without parsing full cmdlines.
Deats,
- `set_actor_proctitle()` wraps the `setproctitle`
pkg with `ImportError` guard; optional at runtime
but listed in `pyproject.toml` so default installs
benefit.
- called early in `_child._actor_child_main()` after
`Actor` construction, before `_trio_main()` entry.
- tests in `tests/devx/test_proctitle.py`: format
unit test, `/proc/{cmdline,comm}` integration
test, negative detection test.
Resolves#457
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code