Feature/viewer annotation toggle (#4557)

# Description of Changes

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Please provide a summary of the changes, including:

- What was changed
- Why the change was made
- Any challenges encountered

Closes #(issue_number)
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---

## 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.

---------

Co-authored-by: Copilot <[email protected]>
Co-authored-by: James Brunton <[email protected]>

frontend/src/components/viewer/LocalEmbedPDF.tsx

@@ -42,13 +42,13 @@ import { ExportAPIBridge } from './ExportAPIBridge';
 interface LocalEmbedPDFProps {
   file?: File | Blob;
   url?: string | null;
-  enableSignature?: boolean;
+  enableAnnotations?: boolean;
   onSignatureAdded?: (annotation: any) => void;
   signatureApiRef?: React.RefObject<SignatureAPI>;
   historyApiRef?: React.RefObject<HistoryAPI>;
 }
 
-export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureAdded, signatureApiRef, historyApiRef }: LocalEmbedPDFProps) {
+export function LocalEmbedPDF({ file, url, enableAnnotations = false, onSignatureAdded, signatureApiRef, historyApiRef }: LocalEmbedPDFProps) {
   const [pdfUrl, setPdfUrl] = useState<string | null>(null);
   const [, setAnnotations] = useState<Array<{id: string, pageIndex: number, rect: any}>>([]);
 
@@ -93,10 +93,10 @@ export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureA
       createPluginRegistration(SelectionPluginPackage),
 
       // Register history plugin for undo/redo (recommended for annotations)
-      ...(enableSignature ? [createPluginRegistration(HistoryPluginPackage)] : []),
+      ...(enableAnnotations ? [createPluginRegistration(HistoryPluginPackage)] : []),
 
       // Register annotation plugin (depends on InteractionManager, Selection, History)
-      ...(enableSignature ? [createPluginRegistration(AnnotationPluginPackage, {
+      ...(enableAnnotations ? [createPluginRegistration(AnnotationPluginPackage, {
         annotationAuthor: 'Digital Signature',
         autoCommit: true,
         deactivateToolAfterCreate: false,
@@ -194,7 +194,7 @@ export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureA
       <EmbedPDF
         engine={engine}
         plugins={plugins}
-        onInitialized={enableSignature ? async (registry) => {
+        onInitialized={enableAnnotations ? async (registry) => {
           const annotationPlugin = registry.getPlugin('annotation');
           if (!annotationPlugin || !annotationPlugin.provides) return;
 
@@ -265,8 +265,8 @@ export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureA
         <SearchAPIBridge />
         <ThumbnailAPIBridge />
         <RotateAPIBridge />
-        {enableSignature && <SignatureAPIBridge ref={signatureApiRef} />}
-        {enableSignature && <HistoryAPIBridge ref={historyApiRef} />}
+        {enableAnnotations && <SignatureAPIBridge ref={signatureApiRef} />}
+        {enableAnnotations && <HistoryAPIBridge ref={historyApiRef} />}
         <ExportAPIBridge />
         <GlobalPointerProvider>
           <Viewport
@@ -312,7 +312,7 @@ export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureA
                     {/* Selection layer for text interaction */}
                     <SelectionLayer pageIndex={pageIndex} scale={scale} />
                     {/* Annotation layer for signatures (only when enabled) */}
-                    {enableSignature && (
+                    {enableAnnotations && (
                       <AnnotationLayer
                         pageIndex={pageIndex}
                         scale={scale}