Feature/v2/redact (#5249)

# Description of Changes

- Add manual redaction and added it to the right rail in the viewer

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

frontend/src/core/components/layout/Workbench.tsx

@@ -1,9 +1,10 @@
+import { useCallback } from 'react';
 import { Box } from '@mantine/core';
 import { useRainbowThemeContext } from '@app/components/shared/RainbowThemeProvider';
 import { useToolWorkflow } from '@app/contexts/ToolWorkflowContext';
 import { useFileHandler } from '@app/hooks/useFileHandler';
 import { useFileState } from '@app/contexts/FileContext';
-import { useNavigationState, useNavigationActions } from '@app/contexts/NavigationContext';
+import { useNavigationState, useNavigationActions, useNavigationGuard } from '@app/contexts/NavigationContext';
 import { isBaseWorkbench } from '@app/types/workbench';
 import { useViewer } from '@app/contexts/ViewerContext';
 import { useAppConfig } from '@app/contexts/AppConfigContext';
@@ -51,6 +52,21 @@ export default function Workbench() {
 
   // Get active file index from ViewerContext
   const { activeFileIndex, setActiveFileIndex } = useViewer();
+  
+  // Get navigation guard for unsaved changes check when switching files
+  const { requestNavigation } = useNavigationGuard();
+
+  // Wrap file selection to check for unsaved changes before switching
+  // requestNavigation will show the modal if there are unsaved changes, otherwise navigate immediately
+  const handleFileSelect = useCallback((index: number) => {
+    // Don't do anything if selecting the same file
+    if (index === activeFileIndex) return;
+    
+    // requestNavigation handles the unsaved changes check internally
+    requestNavigation(() => {
+      setActiveFileIndex(index);
+    });
+  }, [activeFileIndex, requestNavigation, setActiveFileIndex]);
 
   const handlePreviewClose = () => {
     setPreviewFile(null);
@@ -182,7 +198,7 @@ export default function Workbench() {
             return { fileId: f.fileId, name: f.name, versionNumber: stub?.versionNumber };
           })}
           currentFileIndex={activeFileIndex}
-          onFileSelect={setActiveFileIndex}
+          onFileSelect={handleFileSelect}
         />
       )}