Fix failing tests for agent framework updates

Updated test fixtures and expectations to match new agent naming:
- Fixed test registry to use correct agent names (setupRepository, keepaTodofile, keepaChangelog)
- Updated test assertions to expect new agent names instead of old ones
- Added missing category fields to test agent definitions
- Enhanced test registry with keepaChangelog agent for complete template testing

All 24 tests now pass:
- test_core.py: 6 tests ✅
- test_installer.py: 10 tests ✅
- test_registry.py: 8 tests ✅

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

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

tests/test_registry.py

@@ -173,8 +173,8 @@ def test_agent_registry_get_templates(tmp_path):
     assert "comprehensive" in templates
 
     # Check that templates contain expected agents
-    assert "setup-repository" in templates["python-basic"]
-    assert "todo-keeper" in templates["python-basic"]
+    assert "setupRepository" in templates["python-basic"]
+    assert "keepaTodofile" in templates["python-basic"]
 
 
 def test_agent_registry_validate_agents(tmp_path):