fix(pdf): correct parse status handling and loader display logic

Update PDF viewer and document hook to improve parse status management:
- Set parseStatus to null on clear instead of 'pending' for accurate state
- Explicitly set initial parseStatus and reset parseProgress when loading a new document
- Adjust loader display logic to check for resolved parse status before showing expanded loader

Prevents UI inconsistencies and ensures parse progress is reflected correctly during document transitions.

src/app/(app)/pdf/[id]/page.tsx

@@ -76,12 +76,14 @@ export default function PDFViewerPage() {
   const clearCurrDocRef = useRef(clearCurrDoc);
   const [isNavigatingBack, setIsNavigatingBack] = useState(false);
   const parseUiState: NonNullable<typeof parseStatus> = parseStatus ?? 'pending';
+  const hasResolvedParseStatus = parseStatus !== null;
   const isParseReady = parseUiState === 'ready';
   const forceReparseDisabled = isForceReparseDisabled(parseStatus);
   const hasRealParseProgress = !!parseProgress
     && parseProgress.totalPages > 0
     && parseProgress.pagesParsed >= 0;
   const shouldShowExpandedParseLoader = !isLoading
+    && hasResolvedParseStatus
     && (parseUiState === 'pending' || parseUiState === 'running' || parseUiState === 'failed' || hasRealParseProgress);
 
   useEffect(() => {

src/app/(app)/pdf/[id]/usePdfDocument.ts

@@ -450,7 +450,7 @@ export function usePdfDocument(): PdfDocumentState {
       setCurrDocName(undefined);
       setCurrDocData(undefined);
       setParsedDocument(null);
-      setParseStatus('pending');
+      setParseStatus(null);
       setParseProgress(null);
       setDocumentSettings(DEFAULT_DOCUMENT_SETTINGS);
 
@@ -461,7 +461,10 @@ export function usePdfDocument(): PdfDocumentState {
         return false;
       }
       if (meta.type === 'pdf') {
-        startParsedPolling(id, (meta.parseStatus ?? null) as PdfParseStatus | null);
+        const initialParseStatus = (meta.parseStatus ?? null) as PdfParseStatus | null;
+        setParseStatus(initialParseStatus);
+        setParseProgress(null);
+        startParsedPolling(id, initialParseStatus);
         void fetchDocumentSettings(id, controller.signal);
       }