Port internal `tractor._<mod>` references to their
new public or reorganized paths after `tractor`
refactored its subpkg layout.
Deats,
- `tractor._portal.Portal` -> `tractor.Portal`.
- `tractor._supervise.ActorNursery` -> `tractor.ActorNursery`.
- `tractor._multiaddr` -> `tractor.discovery._multiaddr`.
- `tractor._addr` -> `tractor.discovery._addr`.
- `tractor._state._runtime_vars` -> `tractor.runtime._state._runtime_vars`.
- `tractor._state.is_debug_mode()` -> `tractor.runtime._state.is_debug_mode()`.
Files touched: `brokers/data.py`, `cli/__init__.py`, `data/feed.py`,
`service/_actor_runtime.py`, `service/_mngr.py`, `storage/cli.py`,
`tsp/_annotate.py`, `ui/kivy/monitor.py`, `ui/kivy/option_chain.py`.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code