diff --git a/.gitignore b/.gitignore
index ada3f1a..8d4291a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,8 @@ Thumbs.db
 *.swo
 *~
 
+.qodana-reports/
+
 # Environment
 .env
 .env.local
diff --git a/backend/openmlr/services/session_manager.py b/backend/openmlr/services/session_manager.py
index d59d7b1..4a26da1 100644
--- a/backend/openmlr/services/session_manager.py
+++ b/backend/openmlr/services/session_manager.py
@@ -86,11 +86,11 @@ async def get_or_create_session(
 
         session = Session(config=config, conversation_id=conversation_id)
 
-        # Determine effective compute node
-        effective_node = None
+        ops = None
         if user_id and db:
             try:
-                from ..db import operations as ops
+                from openmlr.db import operations as ops_module
+                ops = ops_module.operations
                 # Check conversation override
                 conv = await ops.get_conversation_by_id(db, conversation_id)
                 if conv and conv.extra:
diff --git a/backend/openmlr/tools/compute_tools.py b/backend/openmlr/tools/compute_tools.py
index 2d6c0c9..fa9ca9f 100644
--- a/backend/openmlr/tools/compute_tools.py
+++ b/backend/openmlr/tools/compute_tools.py
@@ -69,6 +69,7 @@ async def _handle_probe(node_name: str, user_id: int = None, db=None, **kwargs):
 
     try:
         wm = WorkspaceManager()
+        sm: SandboxManager | None = None
         sm = SandboxManager(workspace_manager=wm)
         await sm.create(node.type, node.config)
         sandbox = sm.get_active()
@@ -115,7 +116,8 @@ async def _handle_probe(node_name: str, user_id: int = None, db=None, **kwargs):
 
     except Exception as e:
         try:
-            await sm.destroy()
+            if sm is not None:
+                await sm.destroy()
         except Exception:
             pass
         await ops.update_compute_node(
diff --git a/backend/tests/test_agent_loop.py b/backend/tests/test_agent_loop.py
index dab8179..a430bf3 100644
--- a/backend/tests/test_agent_loop.py
+++ b/backend/tests/test_agent_loop.py
@@ -343,8 +343,6 @@ async def test_cancelled_returns_none(self, mock_session):
 
         async def mock_stream(messages, config, tools):
             yield "Hello"
-            if False:
-                yield
 
         with patch("openmlr.agent.loop.LLMProvider.generate_stream") as mock_str:
             mock_str.return_value = mock_stream(None, None, None)
diff --git a/qodana.yaml b/qodana.yaml
index 9a4826a..b04a6de 100644
--- a/qodana.yaml
+++ b/qodana.yaml
@@ -8,3 +8,5 @@ profile:
   name: qodana.recommended
 include:
   - name: CheckDependencyLicenses
+exclude:
+  - name: PyTypeHintsInspection