Feature/v2/selected pageeditor rework (#4756)

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

frontend/src/core/hooks/useWheelZoom.ts

@@ -0,0 +1,83 @@
+import { RefObject, useEffect } from 'react';
+
+interface UseWheelZoomOptions {
+  /**
+   * Element the wheel listener should be bound to.
+   */
+  ref: RefObject<Element | null>;
+  /**
+   * Callback executed when the hook decides to zoom in.
+   */
+  onZoomIn: () => void;
+  /**
+   * Callback executed when the hook decides to zoom out.
+   */
+  onZoomOut: () => void;
+  /**
+   * Whether the wheel listener should be active.
+   */
+  enabled?: boolean;
+  /**
+   * How much delta needs to accumulate before a zoom action is triggered.
+   * Defaults to 10 which matches the previous implementations.
+   */
+  threshold?: number;
+  /**
+   * Whether a Ctrl/Cmd modifier is required for zooming. Defaults to true so
+   * we only react to pinch gestures and intentional ctrl+wheel zooming.
+   */
+  requireModifierKey?: boolean;
+}
+
+/**
+ * Shared hook for handling wheel-based zoom across components.
+ * It normalises accumulated delta behaviour, prevents default scrolling when
+ * zoom is triggered, and keeps the handler detached when disabled.
+ */
+export function useWheelZoom({
+  ref,
+  onZoomIn,
+  onZoomOut,
+  enabled = true,
+  threshold = 10,
+  requireModifierKey = true,
+}: UseWheelZoomOptions) {
+  useEffect(() => {
+    if (!enabled) {
+      return;
+    }
+
+    const element = ref.current;
+    if (!element) {
+      return;
+    }
+
+    let accumulator = 0;
+
+    const handleWheel = (event: Event) => {
+      const wheelEvent = event as WheelEvent;
+      const hasModifier = wheelEvent.ctrlKey || wheelEvent.metaKey;
+      if (requireModifierKey && !hasModifier) {
+        return;
+      }
+
+      wheelEvent.preventDefault();
+      wheelEvent.stopPropagation();
+
+      accumulator += wheelEvent.deltaY;
+
+      if (accumulator <= -threshold) {
+        onZoomIn();
+        accumulator = 0;
+      } else if (accumulator >= threshold) {
+        onZoomOut();
+        accumulator = 0;
+      }
+    };
+
+    element.addEventListener('wheel', handleWheel, { passive: false });
+    return () => {
+      element.removeEventListener('wheel', handleWheel);
+    };
+  }, [ref, onZoomIn, onZoomOut, enabled, threshold, requireModifierKey]);
+}