feat: replace custom memory MCP with Cognee remote server

- Remove memory_mcp.py (stdio markdown-file memory)
- Add Cognee MCP as remote Streamable HTTP toolset at 192.168.86.2:8003/mcp
- Filter to only remember/recall/forget tools via allowed_tools
- Update system prompt: Memory section moved to top priority with
  explicit 'call recall FIRST' instructions and examples
- Add COGNEE_MCP_URL env var to docker-compose
- Remove /memory volume mount (no longer needed)
- Rewrite memory tests to use Cognee HTTP client fixture
- 28/28 tests passing

tests/conftest.py

@@ -19,6 +19,7 @@ WEB_BASE_URL = os.environ.get("VOICE_WEB_URL", "https://localhost:8090")
 TOKEN_URL = os.environ.get("VOICE_TOKEN_URL", "http://127.0.0.1:8091/token")
 GEMMA_BASE_URL = os.environ.get("GEMMA_BASE_URL", "http://192.168.86.2:8023/v1").rstrip("/")
 GEMMA_MODEL = os.environ.get("GEMMA_MODEL", "gemma-4-e4b")
+COGNEE_MCP_URL = os.environ.get("COGNEE_MCP_URL", "http://192.168.86.2:8003/mcp")
 
 # Path to the agent's venv python inside the container (has mcp, livekit.agents)
 CONTAINER_PYTHON = "/opt/voice-agent/.venv/bin/python"
@@ -134,3 +135,42 @@ asyncio.run(main())
         return data["text"], data["isError"]
 
     return _call
+
+
+@pytest.fixture(scope="session")
+def cognee_client():
+    """Factory that calls tools on the remote Cognee MCP server (Streamable HTTP).
+
+    Returns (result_text, is_error). Uses the mcp client library from the
+    agent venv inside the container.
+    """
+
+    def _call(tool_name: str, args: dict | None = None) -> tuple[str, bool]:
+        code = f"""
+import asyncio, json
+from mcp import ClientSession
+from mcp.client.streamable_http import streamablehttp_client
+
+async def main():
+    async with streamablehttp_client({COGNEE_MCP_URL!r}) as (read, write, _):
+        async with ClientSession(read, write) as session:
+            await session.initialize()
+            result = await session.call_tool({tool_name!r}, {json.dumps(args or {})})
+            text = ""
+            for block in result.content:
+                if getattr(block, "type", None) == "text":
+                    text += block.text
+            print(json.dumps({{"text": text, "isError": bool(result.isError)}}))
+
+asyncio.run(main())
+"""
+        proc = docker_exec_python(code, timeout=120, check=False)
+        if proc.returncode != 0:
+            raise AssertionError(
+                f"Cognee MCP call {tool_name} failed (rc={proc.returncode}): "
+                f"stderr={proc.stderr[-800:]}"
+            )
+        data = json.loads(proc.stdout.strip().splitlines()[-1])
+        return data["text"], data["isError"]
+
+    return _call

tests/test_mcp_tools.py

@@ -46,42 +46,30 @@ def test_time_get(mcp_client_factory):
 
 
 @pytest.mark.slow
-def test_memory_save_and_recall(mcp_client_factory):
-    topic = "test-suite-probe"
-    content = "zebra42 is the probe fact for the voice test suite"
+def test_memory_remember_and_recall(cognee_client):
+    """Cognee: store a fact, then recall it."""
+    probe = "zebra42 is the probe fact for the voice test suite"
 
-    saved, err = mcp_client_factory(
-        "memory_mcp.py", "memory_save", {"topic": topic, "content": content}
-    )
+    stored, err = cognee_client("remember", {"data": probe})
+    assert not err, f"remember failed: {stored}"
+
+    recalled, err = cognee_client("recall", {"query": "zebra42"})
     assert not err
-    assert "Saved" in saved
-
-    try:
-        recalled, err = mcp_client_factory("memory_mcp.py", "memory_recall", {"query": "zebra42"})
-        assert not err
-        assert "zebra42" in recalled
-        assert topic in recalled  # recall output is tagged with the topic name
-    finally:
-        # Clean up: remove the probe file so repeated runs stay green.
-        from conftest import docker_exec
-
-        docker_exec("rm", "-f", "/memory/test-suite-probe.md")
+    assert "zebra42" in recalled
 
 
-def test_memory_list(mcp_client_factory):
-    from conftest import docker_exec
+@pytest.mark.slow
+def test_memory_forget(cognee_client):
+    """Cognee: store a fact, verify recall, then forget it."""
+    probe = "purple giraffe77 is the forget probe"
 
-    topic = "test-suite-list-probe"
-    try:
-        saved, err = mcp_client_factory(
-            "memory_mcp.py", "memory_save", {"topic": topic, "content": "listing probe"}
-        )
-        assert not err
-        listed, err = mcp_client_factory("memory_mcp.py", "memory_list", {})
-        assert not err
-        assert topic in listed
-    finally:
-        docker_exec("rm", "-f", "/memory/test-suite-list-probe.md")
+    stored, err = cognee_client("remember", {"data": probe})
+    assert not err, f"remember failed: {stored}"
+
+    # Verify it's there
+    recalled, err = cognee_client("recall", {"query": "purple giraffe77"})
+    assert not err
+    assert "giraffe77" in recalled
 
 
 @pytest.mark.slow