Modernized codebase with tooling configuration and CI/CD workflows.

- Replaced legacy typing (Optional, List, Type, Union, Tuple) with PEP 604/585 equivalents.
- Added pyproject.toml with configurations for hatch-vcs, mypy, ruff, and codespell.
- Added CI workflows for formatting, linting, type checking, and spelling.
- Added CD workflow for building and uploading plugin artifacts on push to master and version tags.
- Added dependency auditing workflow with pip-audit.
- Added comprehensive docstrings and inline comments across all modules.
- Fixed User-Agent header using hardcoded version instead of actual plugin version.
- Fixed grammar and terminology in log messages and comments.
- Removed unreachable error handling branch in unsubscribe command.

owncastsentry/config.py

@@ -1,8 +1,18 @@
 # Copyright 2026 Logan Fick
 #
-# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at: https://www.apache.org/licenses/LICENSE-2.0
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
 #
-# Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Configuration module for the OwncastSentry plugin."""
 
 from mautrix.util.config import BaseProxyConfig, ConfigUpdateHelper
 
@@ -11,19 +21,13 @@ class Config(BaseProxyConfig):
     """Configuration class for OwncastSentry plugin."""
 
     def do_update(self, helper: ConfigUpdateHelper) -> None:
-        """
-        Update configuration with user-provided values.
+        """Update configuration with user-provided values.
 
         :param helper: ConfigUpdateHelper for copying values.
-        :return: Nothing.
         """
         helper.copy("health_check_endpoint")
 
     @property
     def health_check_endpoint(self) -> str:
-        """
-        Get the health check endpoint URL.
-
-        :return: The configured endpoint URL or empty string if not set.
-        """
-        return self["health_check_endpoint"]
+        """Return the configured health check endpoint URL."""
+        return self["health_check_endpoint"]  # type: ignore[no-any-return]