fix: load pipeline stats in syncFileStatus and handle missing pipeline data

Problem:
- syncFileStatus() doesn't load pipeline progress data
- Files stuck in 'processing' without percentage display
- pollPipelineProgress() not started when pipeline data missing

Solution:
1. Add loadPipelineStats() call in syncFileStatus() for processing files
2. Start pollPipelineProgress() even when pipeline data is missing
3. Ensure progress bar always has data to display

Impact:
- Progress bar now shows percentage during deep scan
- Files no longer stuck in 'processing' state indefinitely
- Better handling of edge cases when API data is missing

Related: Core team needs to verify get_pipeline_stats API accuracy

src/views/LibraryView.vue

@@ -786,7 +786,7 @@ async function loadFiles() {
       } else if (pipeline && pipeline.overall_progress >= 1.0) {
         f.status = 'completed'
       } else if (!pipeline && f.status === 'processing') {
-        f.status = 'registered'
+        pollPipelineProgress(f.file_uuid)
       }
       
       await loadFileStats(f.file_uuid, true)