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_long_term.py

@@ -0,0 +1,30 @@
+"""
+Tests for LongTermMemory.
+"""
+
+import pytest
+from dcos.memory.long_term import LongTermMemory, Importance
+
+
+class TestLongTermMemory:
+    def test_commit_and_recall(self):
+        mem = LongTermMemory()
+        mem.commit("important_fact", "AI is valuable", Importance.HIGH)
+        assert mem.recall("important_fact") == "AI is valuable"
+
+    def test_recall_missing(self):
+        mem = LongTermMemory()
+        assert mem.recall("nonexistent") is None
+
+    def test_consolidate(self):
+        mem = LongTermMemory()
+        count = mem.consolidate({"temp": "data"})
+        assert count == 1
+        assert mem.recall("temp") == "data"
+
+    def test_search(self):
+        mem = LongTermMemory()
+        mem.commit("python_info", "Python is a language", Importance.MEDIUM)
+        mem.commit("java_info", "Java is a language", Importance.MEDIUM)
+        results = mem.search("python")
+        assert len(results) > 0