fix: use stepId instead of type to check series_sync completion

The type field is 'system_progress' for SYSTEM progress events,
not 'series_sync'. Use stepId to correctly identify when
series_sync has completed.

src/server/web/templates/loading.html

@@ -451,7 +451,8 @@
             updateStep(stepId, status, msg, percent, current, total);
 
             // Check for completion of series_sync
-            if (metadata?.initialization_complete || type === 'series_sync' && status === 'completed') {
+            // stepId is used because type is 'system_progress' for SYSTEM progress events
+            if (metadata?.initialization_complete || (stepId === 'series_sync' && status === 'completed')) {
                 // For initial phase, series_sync completion leads to /setup/unresolved
                 handleSeriesSyncComplete();
             }