Clean up dead code, fix type errors, and add publish workflow

Remove unused _append_ops_call_method, fix _property_data_from_member
call signature, replace sys.version_info guard with hasattr check for
__buffer__ protocol, fix implicit string concatenations, add msgbus
overrides for 4.0-4.4, add conformance tests, and add publish script.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

uv.lock

@@ -62,6 +62,7 @@ dev = [
     { name = "black" },
     { name = "poethepoet" },
     { name = "ruff" },
+    { name = "typing-extensions" },
 ]
 
 [package.metadata]
@@ -72,6 +73,7 @@ dev = [
     { name = "black", specifier = ">=26.3.1" },
     { name = "poethepoet", specifier = ">=0.42.1" },
     { name = "ruff", specifier = ">=0.15.6" },
+    { name = "typing-extensions", specifier = ">=4.15.0" },
 ]
 
 [[package]]
@@ -282,3 +284,12 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/89/7a/09ece68445ceac348df06e08bf75db72d0e8427765b96c9c0ffabc1be1d9/ruff-0.15.6-py3-none-win_amd64.whl", hash = "sha256:aee25bc84c2f1007ecb5037dff75cef00414fdf17c23f07dc13e577883dca406", size = 11787271, upload-time = "2026-03-12T23:05:20.168Z" },
     { url = "https://files.pythonhosted.org/packages/7f/d0/578c47dd68152ddddddf31cd7fc67dc30b7cdf639a86275fda821b0d9d98/ruff-0.15.6-py3-none-win_arm64.whl", hash = "sha256:c34de3dd0b0ba203be50ae70f5910b17188556630e2178fd7d79fc030eb0d837", size = 11060497, upload-time = "2026-03-12T23:05:25.968Z" },
 ]
+
+[[package]]
+name = "typing-extensions"
+version = "4.15.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/72/94/1a15dd82efb362ac84269196e94cf00f187f7ed21c242792a923cdb1c61f/typing_extensions-4.15.0.tar.gz", hash = "sha256:0cea48d173cc12fa28ecabc3b837ea3cf6f38c6d1136f85cbaaf598984861466", size = 109391, upload-time = "2025-08-25T13:49:26.313Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/18/67/36e9267722cc04a6b9f15c7f3441c2363321a3ea07da7ae0c0707beb2a9c/typing_extensions-4.15.0-py3-none-any.whl", hash = "sha256:f0fa19c6845758ab08074a0cfa8b7aecb71c999ca73d62883bc25cc018c4e548", size = 44614, upload-time = "2025-08-25T13:49:24.86Z" },
+]