Provide import-free runtime aliases for annotation-only actor and
multiaddr types so `typing.get_type_hints()` remains usable without
eagerly loading optional dependencies.
Correct `_address_types` to its actual `dict` shape and cover the
affected discovery and transport APIs.
Caught-during: review remediation
Found-via: `/run-tests` test_lazy_annotation_names_resolve
Review: PR #478 (goodboy)
https://github.com/goodboy/tractor/pull/478#pullrequestreview-4922213201
(this patch was generated in some part by `opencode` using
`gpt-5.6-sol` (`openai`))
Gud Boi