Export __version__ via __all__

PEP 396 convention: ``__version__`` is the canonical public
module-level version handle. Add it to ``__all__`` so
``from dqlitewire import *`` binds it and static-analysis tools that
treat ``__all__`` as the source of truth see it as public — matching
python-dqlite-dbapi which already advertises it this way.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: antoineleclair

src/dqlitewire/__init__.py

@@ -69,6 +69,7 @@
 
 __all__ = [
     "ContinuationError",
+    "__version__",
     "DecodeError",
     "EncodeError",
     "HandshakeError",

tests/test_version.py

@@ -11,3 +11,14 @@ def test_pyproject_matches_package_version() -> None:
     with pyproject.open("rb") as f:
         metadata = tomllib.load(f)
     assert metadata["project"]["version"] == dqlitewire.__version__
+
+
+def test_version_is_in_all() -> None:
+    """Pin ``__version__`` as a public, re-exported attribute.
+
+    PEP 396 convention: ``__version__`` is the canonical module-level
+    handle for version discovery and belongs in ``__all__`` so
+    ``from dqlitewire import *`` binds it and static-analysis tools
+    that read ``__all__`` as the source of truth see it as public.
+    """
+    assert "__version__" in dqlitewire.__all__