feat: implement DCOS source tree, tests, and build configuration

Complete implementation of the DCOS package including:
- 40+ Python source files across agents, communication, core, learning, memory, protocols, utils
- pyproject.toml build configuration
- 102 unit tests across all subsystems
- Fixed flake.nix (Python 3.12, proper dependencies, pyproject build)
- Fixed .woodpecker.yml (correct paths, removed silent-fail flags)
- Added .gitignore
- Cleared stale pytest cache

tests/test_protocols/__init__.py

@@ -0,0 +1 @@
+"""Protocol tests."""

tests/test_protocols/test_external_tools.py

@@ -0,0 +1,35 @@
+"""
+Tests for ExternalTools.
+"""
+
+import pytest
+from dcos.protocols.external_tools import ExternalTools
+
+
+def sample_handler(param: str) -> str:
+    return f"handled: {param}"
+
+
+class TestExternalTools:
+    def test_register_and_execute(self):
+        tools = ExternalTools()
+        tools.register_tool("sample", sample_handler)
+        result = tools.execute("sample", {"param": "test"})
+        assert result == "handled: test"
+
+    def test_list_tools(self):
+        tools = ExternalTools()
+        tools.register_tool("tool_a", sample_handler)
+        tools.register_tool("tool_b", sample_handler)
+        assert len(tools.list_tools()) == 2
+
+    def test_missing_tool(self):
+        tools = ExternalTools()
+        with pytest.raises(KeyError):
+            tools.execute("nonexistent", {})
+
+    def test_get_result(self):
+        tools = ExternalTools()
+        tools.register_tool("calc", sample_handler)
+        tools.execute("calc", {"param": "42"})
+        assert tools.get_result("calc") == "handled: 42"

tests/test_protocols/test_user_interface.py

@@ -0,0 +1,27 @@
+"""
+Tests for UserInterface.
+"""
+
+import pytest
+from dcos.protocols.user_interface import UserInterface, UserRequest, SystemResponse
+
+
+class TestUserInterface:
+    def test_process_input(self):
+        ui = UserInterface()
+        request = UserRequest(input="hello", user_id="user_1")
+        parsed = ui.process_input(request)
+        assert parsed["intent"] == "query"
+
+    def test_format_response(self):
+        ui = UserInterface()
+        response = SystemResponse(output="Hello!", agent_id="agent_1")
+        formatted = ui.format_response(response)
+        assert "[agent_1]" in formatted
+
+    def test_history(self):
+        ui = UserInterface()
+        ui.format_response(SystemResponse(output="msg1", agent_id="a"))
+        ui.format_response(SystemResponse(output="msg2", agent_id="b"))
+        history = ui.get_history()
+        assert len(history) == 2