feat: Add OCR script for PDFs using Ollama and refine document preview navigation and zoom behavior.

frontend/src/preview/PdfViewer.tsx

@@ -379,7 +379,8 @@ const PdfViewer = ({ src, title, className, viewportRef }: PdfViewerProps): JSX.
   const stackStyle = useMemo<CSSProperties>(() => ({
     '--pdf-viewer-viewport-width': `${viewportWidth}px`,
     '--pdf-viewer-viewport-height': `${viewportHeight}px`,
-  }), [viewportHeight, viewportWidth]);
+    cursor: viewMode === 'fit-width' ? 'zoom-out' : 'zoom-in',
+  }), [viewportHeight, viewportWidth, viewMode]);
 
   const toggleViewMode = useCallback(() => {
     setViewMode((prev) => (prev === 'fit-width' ? 'contain' : 'fit-width'));

frontend/src/preview/PreviewContext.tsx

@@ -21,9 +21,10 @@ export const usePreviewContext = () => {
 interface PreviewProviderProps {
     children: React.ReactNode;
     ensureDownloadUrl?: (docId: Identifier) => Promise<any>;
+    onNavigate?: (documentId: Identifier) => void;
 }
 
-export const PreviewProvider: React.FC<PreviewProviderProps> = ({ children, ensureDownloadUrl }) => {
+export const PreviewProvider: React.FC<PreviewProviderProps> = ({ children, ensureDownloadUrl, onNavigate }) => {
     const [previewDoc, setPreviewDoc] = useState<Document | null>(null);
     const [previewUrl, setPreviewUrl] = useState<string | null>(null);
 
@@ -36,6 +37,13 @@ export const PreviewProvider: React.FC<PreviewProviderProps> = ({ children, ensu
         setPreviewUrl(null);
     }, []);
 
+    const handleMaximize = useCallback(() => {
+        if (previewDoc && onNavigate) {
+            onNavigate(previewDoc.id);
+            closePreview();
+        }
+    }, [previewDoc, onNavigate, closePreview]);
+
     useEffect(() => {
         if (!previewDoc) {
             setPreviewUrl(null);
@@ -87,6 +95,7 @@ export const PreviewProvider: React.FC<PreviewProviderProps> = ({ children, ensu
             <PreviewZoomOverlay
                 open={Boolean(previewUrl)}
                 onClose={closePreview}
+                onMaximize={onNavigate ? handleMaximize : undefined}
                 document={overlayDocument}
             />
         </PreviewContext.Provider>