Keep lazy annotations runtime-resolvable

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`))

tests/test_lazy_imports.py

@@ -0,0 +1,41 @@
+'''
+Regression tests for the cold package import surface.
+
+'''
+from typing import (
+    Any,
+    get_type_hints,
+)
+
+from tractor.discovery import (
+    _addr,
+    _multiaddr,
+)
+from tractor.ipc import (
+    _tcp,
+    _uds,
+)
+
+
+def test_lazy_annotation_names_resolve():
+    '''
+    Resolve annotations without importing optional dependencies.
+
+    Moving annotation-only third-party names under `TYPE_CHECKING`
+    left their runtime globals undefined, causing
+    `typing.get_type_hints()` to raise `NameError`. Resolve every
+    affected API and prove the lazy aliases retain import-free runtime
+    introspection.
+
+    '''
+    assert get_type_hints(_multiaddr.mk_maddr)['return'] is Any
+    assert get_type_hints(_tcp.MsgpackTCPStream.maddr.fget)[
+        'return'
+    ] is Any
+    assert get_type_hints(_uds.MsgpackUDSStream.maddr.fget)[
+        'return'
+    ] == Any|str
+    assert get_type_hints(_addr.Address.get_random)[
+        'current_actor'
+    ] is Any
+    assert _addr.__annotations__['_address_types'].startswith('dict')

tractor/discovery/_addr.py

@@ -16,6 +16,7 @@
 from __future__ import annotations
 from uuid import uuid4
 from typing import (
+    Any,
     Protocol,
     ClassVar,
     Type,
@@ -36,8 +37,9 @@ from ..ipc._uds import UDSAddress
 if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs ~4.5ms
     # of `import tractor` wall-time (gh #470).
-    from bidict import bidict
     from ..runtime._runtime import Actor
+else:
+    Actor = Any
 
 log = get_logger()
 
@@ -172,7 +174,7 @@ class Address(Protocol):
         ...
 
 
-_address_types: bidict[str, Type[Address]] = {
+_address_types: dict[str, Type[Address]] = {
     'tcp': TCPAddress,
     'uds': UDSAddress
 }

tractor/discovery/_multiaddr.py

@@ -27,7 +27,10 @@ Multiaddress support using the upstream `py-multiaddr` lib
 from __future__ import annotations
 import ipaddress
 from pathlib import Path
-from typing import TYPE_CHECKING
+from typing import (
+    Any,
+    TYPE_CHECKING,
+)
 
 if TYPE_CHECKING:
     # NOTE, `multiaddr` is lazy-imported at first use
@@ -35,6 +38,9 @@ if TYPE_CHECKING:
     # `import tractor` path (gh #470).
     from multiaddr import Multiaddr
     from tractor.discovery._addr import Address
+else:
+    Multiaddr = Any
+    Address = Any
 
 # map from tractor-internal `proto_key` identifiers
 # to the standard multiaddr protocol name strings.

tractor/ipc/_tcp.py

@@ -20,6 +20,7 @@ TCP implementation of tractor.ipc._transport.MsgTransport protocol
 from __future__ import annotations
 import ipaddress
 from typing import (
+    Any,
     ClassVar,
     TYPE_CHECKING,
 )
@@ -46,6 +47,8 @@ if TYPE_CHECKING:
     # ONLY type-annots, the eager import costs
     # `import tractor` wall-time (gh #470).
     from multiaddr import Multiaddr
+else:
+    Multiaddr = Any
 
 
 log = get_logger()

tractor/ipc/_uds.py

@@ -32,6 +32,7 @@ from socket import (
 )
 import struct
 from typing import (
+    Any,
     Type,
     TYPE_CHECKING,
     ClassVar,
@@ -66,6 +67,9 @@ if TYPE_CHECKING:
     # `import tractor` wall-time (gh #470).
     from multiaddr import Multiaddr
     from tractor.runtime._runtime import Actor
+else:
+    Multiaddr = Any
+    Actor = Any
 
 
 # Platform-specific credential passing constants