test(backend): add comprehensive tests for OAuth and agent endpoints

- Added tests for OAuth provider admin and consent endpoints covering edge cases.
- Extended agent-related tests to handle incorrect project associations and lifecycle state transitions.
- Introduced tests for sprint status transitions and validation checks.
- Improved multiline formatting consistency across all test functions.

backend/tests/crud/syndarix/test_issue_crud.py

@@ -42,7 +42,9 @@ class TestIssueCreate:
             assert result.story_points == 5
 
     @pytest.mark.asyncio
-    async def test_create_issue_with_external_tracker(self, async_test_db, test_project_crud):
+    async def test_create_issue_with_external_tracker(
+        self, async_test_db, test_project_crud
+    ):
         """Test creating issue with external tracker info."""
         _test_engine, AsyncTestingSessionLocal = async_test_db
 
@@ -182,7 +184,9 @@ class TestIssueAssignment:
     """Tests for issue assignment operations."""
 
     @pytest.mark.asyncio
-    async def test_assign_to_agent(self, async_test_db, test_issue_crud, test_agent_instance_crud):
+    async def test_assign_to_agent(
+        self, async_test_db, test_issue_crud, test_agent_instance_crud
+    ):
         """Test assigning issue to an agent."""
         _test_engine, AsyncTestingSessionLocal = async_test_db
 
@@ -198,7 +202,9 @@ class TestIssueAssignment:
             assert result.human_assignee is None
 
     @pytest.mark.asyncio
-    async def test_unassign_agent(self, async_test_db, test_issue_crud, test_agent_instance_crud):
+    async def test_unassign_agent(
+        self, async_test_db, test_issue_crud, test_agent_instance_crud
+    ):
         """Test unassigning agent from issue."""
         _test_engine, AsyncTestingSessionLocal = async_test_db
 
@@ -237,7 +243,9 @@ class TestIssueAssignment:
             assert result.assigned_agent_id is None
 
     @pytest.mark.asyncio
-    async def test_assign_to_human_clears_agent(self, async_test_db, test_issue_crud, test_agent_instance_crud):
+    async def test_assign_to_human_clears_agent(
+        self, async_test_db, test_issue_crud, test_agent_instance_crud
+    ):
         """Test assigning to human clears agent assignment."""
         _test_engine, AsyncTestingSessionLocal = async_test_db
 
@@ -304,7 +312,9 @@ class TestIssueByProject:
     """Tests for getting issues by project."""
 
     @pytest.mark.asyncio
-    async def test_get_by_project(self, async_test_db, test_project_crud, test_issue_crud):
+    async def test_get_by_project(
+        self, async_test_db, test_project_crud, test_issue_crud
+    ):
         """Test getting issues by project."""
         _test_engine, AsyncTestingSessionLocal = async_test_db
 
@@ -397,7 +407,9 @@ class TestIssueBySprint:
     """Tests for getting issues by sprint."""
 
     @pytest.mark.asyncio
-    async def test_get_by_sprint(self, async_test_db, test_project_crud, test_sprint_crud):
+    async def test_get_by_sprint(
+        self, async_test_db, test_project_crud, test_sprint_crud
+    ):
         """Test getting issues by sprint."""
         _test_engine, AsyncTestingSessionLocal = async_test_db
 
@@ -533,7 +545,11 @@ class TestIssueStats:
 
         # Create issues with various statuses and priorities
         async with AsyncTestingSessionLocal() as session:
-            for status in [IssueStatus.OPEN, IssueStatus.IN_PROGRESS, IssueStatus.CLOSED]:
+            for status in [
+                IssueStatus.OPEN,
+                IssueStatus.IN_PROGRESS,
+                IssueStatus.CLOSED,
+            ]:
                 issue_data = IssueCreate(
                     project_id=test_project_crud.id,
                     title=f"Stats Issue {status.value}",