Fix: Remove episodes from missing list on download/rescan

- Update _update_series_in_db to sync missing episodes bidirectionally
- Add delete_by_series_and_episode method to EpisodeService
- Remove downloaded episodes from DB after successful download
- Clear anime service cache when episodes are removed
- Fix tests to use 'message' instead of 'detail' in API responses
- Mock DB operations in rescan tests

tests/api/test_download_endpoints.py

@@ -236,7 +236,7 @@ async def test_add_to_queue_service_error(
     )
 
     assert response.status_code == 400
-    assert "Queue full" in response.json()["detail"]
+    assert "Queue full" in response.json()["message"]
 
 
 @pytest.mark.asyncio
@@ -294,8 +294,8 @@ async def test_start_download_empty_queue(
 
     assert response.status_code == 400
     data = response.json()
-    detail = data["detail"].lower()
-    assert "empty" in detail or "no pending" in detail
+    message = data["message"].lower()
+    assert "empty" in message or "no pending" in message
 
 
 @pytest.mark.asyncio
@@ -311,8 +311,8 @@ async def test_start_download_already_active(
 
     assert response.status_code == 400
     data = response.json()
-    detail_lower = data["detail"].lower()
-    assert "already" in detail_lower or "progress" in detail_lower
+    message_lower = data["message"].lower()
+    assert "already" in message_lower or "progress" in message_lower
 
 
 @pytest.mark.asyncio

tests/frontend/test_existing_ui_integration.py

@@ -201,7 +201,7 @@ class TestFrontendAnimeAPI:
     
     async def test_rescan_anime(self, authenticated_client):
         """Test POST /api/anime/rescan triggers rescan with events."""
-        from unittest.mock import MagicMock
+        from unittest.mock import MagicMock, patch
 
         from src.server.services.progress_service import ProgressService
         from src.server.utils.dependencies import get_anime_service
@@ -210,7 +210,7 @@ class TestFrontendAnimeAPI:
         mock_series_app = MagicMock()
         mock_series_app.directory_to_search = "/tmp/test"
         mock_series_app.series_list = []
-        mock_series_app.rescan = AsyncMock()
+        mock_series_app.rescan = AsyncMock(return_value=[])
         mock_series_app.download_status = None
         mock_series_app.scan_status = None
         
@@ -232,7 +232,16 @@ class TestFrontendAnimeAPI:
         app.dependency_overrides[get_anime_service] = lambda: anime_service
         
         try:
-            response = await authenticated_client.post("/api/anime/rescan")
+            # Mock database operations called during rescan
+            with patch.object(
+                anime_service, '_save_scan_results_to_db', new_callable=AsyncMock
+            ):
+                with patch.object(
+                    anime_service, '_load_series_from_db', new_callable=AsyncMock
+                ):
+                    response = await authenticated_client.post(
+                        "/api/anime/rescan"
+                    )
             
             assert response.status_code == 200
             data = response.json()
@@ -448,7 +457,7 @@ class TestFrontendJavaScriptIntegration:
         assert response.status_code in [200, 400]
         if response.status_code == 400:
             # Verify error message indicates empty queue
-            assert "No pending downloads" in response.json()["detail"]
+            assert "No pending downloads" in response.json()["message"]
         
         # Test pause - always succeeds even if nothing is processing
         response = await authenticated_client.post("/api/queue/pause")

tests/integration/test_download_flow.py

@@ -220,7 +220,8 @@ class TestDownloadFlowEndToEnd:
         
         assert response.status_code == 400
         data = response.json()
-        assert "detail" in data
+        # API returns 'message' for error responses
+        assert "message" in data
 
     async def test_validation_error_for_invalid_priority(self, authenticated_client):
         """Test validation error for invalid priority level."""

tests/integration/test_websocket_integration.py

@@ -6,7 +6,7 @@ real-time updates are properly broadcasted to connected clients.
 """
 import asyncio
 from typing import Any, Dict, List
-from unittest.mock import Mock, patch
+from unittest.mock import AsyncMock, Mock, patch
 
 import pytest
 
@@ -64,6 +64,9 @@ async def anime_service(mock_series_app, progress_service):
         series_app=mock_series_app,
         progress_service=progress_service,
     )
+    # Mock database operations that are called during rescan
+    service._save_scan_results_to_db = AsyncMock(return_value=0)
+    service._load_series_from_db = AsyncMock(return_value=None)
     yield service
 
 

tests/unit/test_serie_list.py

@@ -1,9 +1,9 @@
 """Tests for SerieList class - identifier standardization."""
+# pylint: disable=redefined-outer-name
 
 import os
 import tempfile
 import warnings
-from unittest.mock import MagicMock, patch
 
 import pytest