fix: derive __version__ from package metadata so it cannot drift

The published wheel reported a version older than itself: oneclaw 0.59.8 said
__version__ == "0.59.6", langchain-1claw 0.2.3 said "0.2.2", and
1claw-crewai-tools 0.3.3 said "0.3.0". Two hand-maintained copies of the same
number, and releases bumped one of them.

__version__ now reads the installed distribution metadata, so pyproject.toml is
the only place a version is written. A test asserts the two agree, and fails if
a literal is ever put back.

Caught by installing the freshly published wheel from PyPI and importing it —
which is worth doing after a release rather than trusting that a green publish
job means the artifact is right.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019d5ks2kCa4eXD1ftdkECPu

Author: kmjones1979

src/oneclaw/__init__.py

@@ -18,8 +18,16 @@
 from oneclaw.resources.sub_orgs import SubOrgsResource
 from oneclaw.types import CredentialSource, OneclawClientConfig, OneclawResponse
 
-__version__ = "0.59.6"
+# Single source of truth: the version lives in pyproject.toml and is read
+# from the installed distribution metadata. A hand-maintained literal here
+# drifts the moment a release bumps one and not the other — 0.59.8 shipped
+# reporting 0.59.6, so anyone checking __version__ got the wrong answer.
+try:  # pragma: no cover - trivial
+    from importlib.metadata import PackageNotFoundError, version as _dist_version
 
+    __version__ = _dist_version("oneclaw")
+except PackageNotFoundError:  # running from a source tree, not installed
+    __version__ = "0+unknown"
 __all__ = [
     "OneclawClient",
     "create_client",

tests/test_version.py

@@ -0,0 +1,29 @@
+# Copyright (C) 2026 1Claw
+# SPDX-License-Identifier: Apache-2.0
+"""The package version must match the one that will be published."""
+
+import importlib
+import pathlib
+import re
+
+
+def test_dunder_version_matches_pyproject() -> None:
+    """__version__ and pyproject.toml must not drift.
+
+    They did: oneclaw 
+    shipped a release whose __version__ named an earlier version, because the
+    literal in __init__.py was hand-maintained alongside the one in
+    pyproject.toml. __version__ now reads the installed distribution metadata,
+    so there is one source of truth; this asserts it stayed that way.
+    """
+    root = pathlib.Path(__file__).resolve().parents[1]
+    declared = re.search(
+        r'^version\s*=\s*"([^"]+)"', (root / "pyproject.toml").read_text(), re.M
+    )
+    assert declared, "pyproject.toml has no version"
+
+    mod = importlib.import_module("oneclaw")
+    assert mod.__version__ == declared.group(1), (
+        f"__version__ is {mod.__version__} but pyproject.toml says {declared.group(1)}; "
+        "a published package would report the wrong version"
+    )