importlib.resources.simple ResourceContainer/ResourceHandle cannot be instantiated

Bug report

Bug description:

Issue

ResourceContainer and ResourceHandle cannot be instantiated because Traversable now declares name as an abstract property. Additionally, ResourceContainer.iterdir() accesses self.reader.resources without calling it, and ResourceHandle.joinpath has a signature mismatch with the base class.

Reproducer

from importlib.resources.simple import ResourceContainer, SimpleReader
import io

class R(SimpleReader):
    @property
    def package(self): return 'x'
    def children(self): return []
    def resources(self): return []
    def open_binary(self, r): return io.BytesIO(b'')

ResourceContainer(R()) # TypeError: Can't instantiate abstract class ResourceContainer

CPython versions tested on:

CPython main branch

Operating systems tested on:

No response

Linked PRs

• gh-145263

Start with importlib.resources.simple and inspect ResourceContainer, ResourceHandle, SimpleReader, and their Traversable relationship. Reproduce the ResourceContainer(R()) failure, then verify the abstract-property, resources access, and joinpath issues are corrected and covered by the relevant tests.