chore: improve governance and resolve lint findings

- Add CONTRIBUTING.md, CHANGELOG.md, and GitHub templates\n- Fix Ruff lint issues (F401, F841)\n- Acknowledge SINT Protocol collaboration proposal in CONTRIBUTING.md

Author: Gemini (Agent)

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,16 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+assignees: ''
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior.
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.

.github/pull_request_template.md

@@ -0,0 +1,10 @@
+## Description
+Describe your changes.
+
+## Related Issue
+Fixes # (issue)
+
+## Type of change
+- [ ] Bug fix (non-breaking change which fixes an issue)
+- [ ] New feature (non-breaking change which adds functionality)
+- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

CHANGELOG.md

@@ -0,0 +1,18 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+## [1.0.1] - 2026-04-19
+### Added
+- `CONTRIBUTING.md` and `CHANGELOG.md` for better project governance.
+- `.github/ISSUE_TEMPLATE` and `PULL_REQUEST_TEMPLATE.md` to support external collaboration.
+
+### Fixed
+- Resolved linting issues (`F401`, `F841`) to improve code health.
+- Blended governance quality scoring with artifact-only checks in Arbiter audits.
+
+## [1.0.0] - 2026-04-01
+### Added
+- Initial release of Agent Governance primitives.
+- `kill_switch.py`, `circuit_breaker.py`, `delegation_token.py`, `governance_bus.py`, and `agent_runner.py`.
+- Full integration test suite.

CONTRIBUTING.md

@@ -0,0 +1,23 @@
+# Contributing to Agent Governance Demo
+
+First off, thank you for considering contributing to this project! It's people like you that make it a great tool for the community.
+
+## Collaboration with SINT Protocol
+We are currently exploring a collaboration with the **SINT Protocol** to use this project as a reference backend for the SINT Python SDK. If you are interested in this effort, please see [Issue #1](https://github.com/hummbl-dev/agent-governance-demo/issues/1).
+
+## Development Setup
+
+1. Clone the repository
+2. Install dependencies: `pip install -e ".[test]"`
+3. Run tests: `python -m pytest`
+
+## PR Process
+
+1. Fork the repo and create your branch from `main`.
+2. Ensure the test suite passes.
+3. If you've added code that should be tested, add tests.
+4. Ensure your code follows the existing style (we use `ruff` for linting).
+5. Open a Pull Request!
+
+## Code Style
+We aim for zero-dependency, standard-library-only implementations. Please avoid adding third-party requirements to the `src/` directory.

src/agent_governance/circuit_breaker.py

@@ -57,7 +57,7 @@ def call(self, fn: Callable[..., Any], *args: Any, **kwargs: Any) -> Any:
             result = fn(*args, **kwargs)
             self._on_success()
             return result
-        except Exception as e:
+        except Exception:
             self._on_failure()
             raise
 

tests/test_governance_bus.py

@@ -1,7 +1,5 @@
 """Tests for the append-only governance bus."""
 
-import pytest
-from pathlib import Path
 from agent_governance.governance_bus import GovernanceBus
 
 

tests/test_kill_switch.py

@@ -2,7 +2,6 @@
 
 import json
 import pytest
-from pathlib import Path
 from agent_governance.kill_switch import KillSwitch, KillSwitchMode, kill_switch_gate