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/viewer/RedactionAPIBridge.tsx

@@ -0,0 +1,60 @@
+import { useEffect, useImperativeHandle } from 'react';
+import { useRedaction as useEmbedPdfRedaction } from '@embedpdf/plugin-redaction/react';
+import { useRedaction } from '@app/contexts/RedactionContext';
+
+/**
+ * RedactionAPIBridge connects the EmbedPDF redaction plugin to our RedactionContext.
+ * It must be rendered inside the EmbedPDF context to access the plugin API.
+ * 
+ * It does two things:
+ * 1. Syncs EmbedPDF state (pendingCount, activeType, isRedacting) to our context
+ * 2. Exposes the EmbedPDF API through our context's ref so outside components can call it
+ */
+export function RedactionAPIBridge() {
+  const { state, provides } = useEmbedPdfRedaction();
+  const { 
+    redactionApiRef, 
+    setPendingCount, 
+    setActiveType, 
+    setIsRedacting,
+    setRedactionsApplied,
+    setBridgeReady
+  } = useRedaction();
+
+  // Mark bridge as ready on mount, not ready on unmount
+  useEffect(() => {
+    setBridgeReady(true);
+    return () => {
+      setBridgeReady(false);
+    };
+  }, [setBridgeReady]);
+
+  // Sync EmbedPDF state to our context
+  useEffect(() => {
+    if (state) {
+      setPendingCount(state.pendingCount ?? 0);
+      setActiveType(state.activeType ?? null);
+      setIsRedacting(state.isRedacting ?? false);
+    }
+  }, [state?.pendingCount, state?.activeType, state?.isRedacting, setPendingCount, setActiveType, setIsRedacting]);
+
+  // Expose the EmbedPDF API through our context's ref
+  useImperativeHandle(redactionApiRef, () => ({
+    toggleRedactSelection: () => {
+      provides?.toggleRedactSelection();
+    },
+    toggleMarqueeRedact: () => {
+      provides?.toggleMarqueeRedact();
+    },
+    commitAllPending: () => {
+      provides?.commitAllPending();
+      // Don't set redactionsApplied here - it should only be set after the file is saved
+      // The save operation in applyChanges will handle setting/clearing this flag
+    },
+    getActiveType: () => state?.activeType ?? null,
+    getPendingCount: () => state?.pendingCount ?? 0,
+  }), [provides, state, setRedactionsApplied]);
+
+  return null;
+}
+