Format updates to instructions and test file

- Improve markdown formatting in instructions.md
- Reorder imports in test_background_loader_session.py per PEP8

docs/instructions.md

@@ -121,10 +121,11 @@ For each task completed:
 
 ✅ **Task Completed Successfully**
 
-### Issue Fixed: TypeError: 'async for' requires an object with __aiter__ method
+### Issue Fixed: TypeError: 'async for' requires an object with **aiter** method
 
 **Problem:**
 The BackgroundLoaderService was crashing when trying to load series data with the error:
+
 ```
 TypeError: 'async for' requires an object with __aiter__ method, got _AsyncGeneratorContextManager
 ```
@@ -136,6 +137,7 @@ The code was incorrectly using `async for db in get_db_session():` to get a data
 
 **Solution:**
 Changed the database session acquisition from:
+
 ```python
 async for db in get_db_session():
     # ... code ...
@@ -143,16 +145,19 @@ async for db in get_db_session():
 ```
 
 To the correct pattern:
+
 ```python
 async with get_db_session() as db:
     # ... code ...
 ```
 
 **Files Modified:**
+
 1. [src/server/services/background_loader_service.py](src/server/services/background_loader_service.py) - Fixed async context manager usage
 2. [tests/unit/test_background_loader_session.py](tests/unit/test_background_loader_session.py) - Created comprehensive unit tests
 
 **Tests:**
+
 - ✅ 5 new unit tests for background loader database session handling (all passing)
 - ✅ Tests verify proper async context manager usage
 - ✅ Tests verify error handling and progress tracking

tests/unit/test_background_loader_session.py

@@ -4,14 +4,15 @@ Unit tests for BackgroundLoaderService database session handling.
 This module tests that the background loader service properly uses async context
 managers for database sessions, preventing TypeError with async for.
 """
-import pytest
-from unittest.mock import AsyncMock, MagicMock, patch
 from datetime import datetime, timezone
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
 
 from src.server.services.background_loader_service import (
     BackgroundLoaderService,
-    SeriesLoadingTask,
     LoadingStatus,
+    SeriesLoadingTask,
 )