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_memory/test_memory_facade.py

@@ -0,0 +1,25 @@
+"""
+Tests for MemoryFacade.
+"""
+
+import pytest
+from dcos.memory.memory_facade import MemoryFacade
+
+
+class TestMemoryFacade:
+    def test_remember_and_recall(self):
+        facade = MemoryFacade()
+        facade.remember("key", "value", importance="low")
+        assert facade.recall("key") == "value"
+
+    def test_search(self):
+        facade = MemoryFacade()
+        facade.remember("important", "data", importance="high")
+        results = facade.search("important")
+        assert "long_term" in results
+
+    def test_summary(self):
+        facade = MemoryFacade()
+        summary = facade.summary()
+        assert "working" in summary
+        assert "episodic" in summary