fix: redirect to /setup/unresolved after series scan completes

- Add 'system_progress' event type to loading page redirect condition
- Add checkUnresolvedAndRedirect() for phase=initial to handle race condition
  where backend initialization completes before WebSocket connects
- Backend now emits series_sync progress events during initial setup
- Loading page checks /api/setup/unresolved immediately on load for phase=initial
- Fixes users getting stuck on loading page after setup

tests/unit/test_initialization_service.py

@@ -771,13 +771,13 @@ class TestScanFoldersToDatabase:
         ) as mock_settings, \
              patch(
                  'src.server.services.initialization_service.SetupService.run',
-                 new_callable=AsyncMock, return_value=1
+                 new_callable=AsyncMock, return_value=(1, 0)
              ) as mock_setup_run:
             mock_settings.anime_directory = anime_dir
 
             result = await _scan_folders_to_database()
 
-        assert result == 1
+        assert result == (1, 0)
         mock_setup_run.assert_called_once()
 
     @pytest.mark.asyncio
@@ -798,13 +798,13 @@ class TestScanFoldersToDatabase:
         ) as mock_settings, \
              patch(
                  'src.server.services.initialization_service.SetupService.run',
-                 new_callable=AsyncMock, return_value=1
+                 new_callable=AsyncMock, return_value=(1, 0)
              ) as mock_setup_run:
             mock_settings.anime_directory = anime_dir
 
             result = await _scan_folders_to_database()
 
-        assert result == 1
+        assert result == (1, 0)
         mock_setup_run.assert_called_once()
 
     @pytest.mark.asyncio
@@ -825,13 +825,13 @@ class TestScanFoldersToDatabase:
         ) as mock_settings, \
              patch(
                  'src.server.services.initialization_service.SetupService.run',
-                 new_callable=AsyncMock, return_value=1
+                 new_callable=AsyncMock, return_value=(1, 0)
              ) as mock_setup_run:
             mock_settings.anime_directory = anime_dir
 
             result = await _scan_folders_to_database()
 
-        assert result == 1
+        assert result == (1, 0)
         mock_setup_run.assert_called_once()
 
     @pytest.mark.asyncio
@@ -852,13 +852,13 @@ class TestScanFoldersToDatabase:
         ) as mock_settings, \
              patch(
                  'src.server.services.initialization_service.SetupService.run',
-                 new_callable=AsyncMock, return_value=1
+                 new_callable=AsyncMock, return_value=(1, 0)
              ) as mock_setup_run:
             mock_settings.anime_directory = anime_dir
 
             result = await _scan_folders_to_database()
 
-        assert result == 1
+        assert result == (1, 0)
         mock_setup_run.assert_called_once()
 
     @pytest.mark.asyncio
@@ -879,13 +879,13 @@ class TestScanFoldersToDatabase:
         ) as mock_settings, \
              patch(
                  'src.server.services.initialization_service.SetupService.run',
-                 new_callable=AsyncMock, return_value=1
+                 new_callable=AsyncMock, return_value=(1, 0)
              ) as mock_setup_run:
             mock_settings.anime_directory = anime_dir
 
             result = await _scan_folders_to_database()
 
-        assert result == 1
+        assert result == (1, 0)
         mock_setup_run.assert_called_once()
 
     @pytest.mark.asyncio
@@ -906,13 +906,13 @@ class TestScanFoldersToDatabase:
         ) as mock_settings, \
              patch(
                  'src.server.services.initialization_service.SetupService.run',
-                 new_callable=AsyncMock, return_value=0
+                 new_callable=AsyncMock, return_value=(0, 0)
              ) as mock_setup_run:
             mock_settings.anime_directory = anime_dir
 
             result = await _scan_folders_to_database()
 
-        assert result == 0
+        assert result == (0, 0)
         mock_setup_run.assert_called_once()
 
     @pytest.mark.asyncio
@@ -923,11 +923,11 @@ class TestScanFoldersToDatabase:
         ) as mock_settings, \
              patch(
                  'src.server.services.initialization_service.SetupService.run',
-                 new_callable=AsyncMock, return_value=0
+                 new_callable=AsyncMock, return_value=(0, 0)
              ) as mock_setup_run:
             mock_settings.anime_directory = None
 
             result = await _scan_folders_to_database()
 
-        assert result == 0
+        assert result == (0, 0)
         mock_setup_run.assert_not_called()