test: add unit tests for delegation infrastructure

Tests for DelegationTask, DelegationResult, delegate_to_librarian:
- Task creation with auto-generated IDs
- Task dependencies and custom IDs
- Successful delegation with result
- Error handling in delegation
- Result preservation

Tests for get_delegation_tools():
- Returns wrapper for members with agent
- Returns raw tools for members without agent
- Handles mixed member types correctly
- Graceful handling of non-existent members

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/core/test_household_registry.py

@@ -294,6 +294,101 @@ class TestHouseholdRegistry:
         assert research_caps[0].name == "research_tools"
 
 
+class TestGetDelegationTools:
+    """Test get_delegation_tools() method for agent-as-tool pattern."""
+
+    def test_delegation_tools_returns_wrapper_for_member_with_agent(self, registry, sample_tools):
+        """Test delegation tools returns wrapper when member has an agent."""
+        from unittest.mock import Mock
+
+        cap = HouseholdCapability(
+            name="librarian",
+            role="The Librarian",
+            category="research",
+            description="Research and wiki management",
+            domains=["research", "wiki"],
+            cost="medium",
+            requires_network=True,
+        )
+
+        mock_agent = Mock()
+        registry.register("librarian", cap, sample_tools, agent=mock_agent)
+
+        tools = registry.get_delegation_tools(["librarian"])
+
+        # Should return delegation wrapper, not raw tools
+        assert len(tools) == 1
+        # The wrapper should be the delegate_to_librarian function
+        assert callable(tools[0])
+        assert tools[0].__name__ == "delegate_to_librarian"
+
+    def test_delegation_tools_returns_raw_tools_for_member_without_agent(self, registry, sample_capability, sample_tools):
+        """Test delegation tools returns raw tools when member has no agent."""
+        registry.register("test_tools", sample_capability, sample_tools)
+
+        tools = registry.get_delegation_tools(["test_tools"])
+
+        # Should return raw tools since no agent
+        assert len(tools) == 2
+        assert tools[0].name == "test_tool_1"
+        assert tools[1].name == "test_tool_2"
+
+    def test_delegation_tools_mixed_members(self, registry, sample_tools):
+        """Test delegation tools handles mix of agent and non-agent members."""
+        from unittest.mock import Mock
+
+        # Member with agent (librarian)
+        librarian_cap = HouseholdCapability(
+            name="librarian",
+            role="The Librarian",
+            category="research",
+            description="Research and wiki",
+            domains=["research"],
+            cost="medium",
+            requires_network=True,
+        )
+        mock_agent = Mock()
+        registry.register("librarian", librarian_cap, sample_tools, agent=mock_agent)
+
+        # Member without agent (tatlock_core)
+        core_cap = HouseholdCapability(
+            name="tatlock_core",
+            role="Butler's Core Tools",
+            category="core",
+            description="Basic tools",
+            domains=["computation"],
+            cost="low",
+            requires_network=False,
+        )
+        registry.register("tatlock_core", core_cap, sample_tools)
+
+        # Request both
+        tools = registry.get_delegation_tools(["librarian", "tatlock_core"])
+
+        # Should get 1 delegation wrapper + 2 raw tools = 3 total
+        assert len(tools) == 3
+
+        # First should be delegation wrapper
+        assert callable(tools[0])
+        assert tools[0].__name__ == "delegate_to_librarian"
+
+        # Rest should be raw tools
+        assert hasattr(tools[1], 'name')
+        assert hasattr(tools[2], 'name')
+
+    def test_delegation_tools_nonexistent_member(self, registry):
+        """Test delegation tools handles non-existent member gracefully."""
+        tools = registry.get_delegation_tools(["nonexistent"])
+
+        assert tools == []
+
+    def test_delegation_tools_empty_list(self, registry):
+        """Test delegation tools handles empty list."""
+        tools = registry.get_delegation_tools([])
+
+        assert tools == []
+
+
 class TestGlobalRegistry:
     """Test the global registry instance."""