Fix linting violations for v1.0.0 release preparation

- Apply black formatting to all Python files
- Fix various flake8 violations in agent system code
- Clean up imports and whitespace issues

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Makefile

@@ -730,7 +730,7 @@ release-check: $(VENV)/bin/activate
 	echo "📋 Release Readiness Checklist:"; \
 	echo "==============================="; \
 	echo "  • Version Consistency:"; \
-	CHANGELOG_VERSION=$$(grep '^## \[' CHANGELOG.md | head -1 | sed 's/## \[\(.*\)\].*/\1/' | grep -v "Unreleased" || echo ""); \
+	CHANGELOG_VERSION=$$(grep '^## \[' CHANGELOG.md | grep -v "Unreleased" | head -1 | sed 's/## \[\(.*\)\].*/\1/' || echo ""); \
 	PYPROJECT_VERSION=$$(grep '^version = ' pyproject.toml | sed 's/version = "\(.*\)"/\1/' || echo ""); \
 	if [ "$$CHANGELOG_VERSION" = "$$PYPROJECT_VERSION" ] && [ -n "$$CHANGELOG_VERSION" ]; then \
 		echo "    ✅ Versions consistent: $$CHANGELOG_VERSION"; \