Add magnifying glass feature with Alt+A keyboard shortcut

[Copilot]

Overview

Implements a magnifying glass feature that allows users to view magnified portions of an image by holding the mouse over it. The feature is activated/deactivated using the Alt+A keyboard shortcut.

Changes

Feature Implementation

• Added a new magnifying glass mode that displays a circular 128px × 128px magnifying glass overlay
• The magnifying glass shows a 2x scaled view of the area under the cursor
• Visual design includes a black 2px border around the circular magnifying glass for clear visibility

Keyboard Shortcut

• Alt+A: Toggle magnifying glass mode on/off
• When active, the cursor changes to a crosshair to indicate the mode is enabled
• The magnifying glass follows the mouse cursor as it moves over the image

Mode Management

• Magnifying mode is mutually exclusive with other editing modes (crop, draw, etc.)
• Switching to other modes automatically deactivates magnifying mode
• Clicking mode buttons (resize, crop, filter, rotate, paint) resets the magnifying flag

Technical Details

• Added magnifyFlag state to ImageLayer class to track magnifying mode status
• Implemented magnifying glass rendering using HTML5 canvas circular clipping and drawImage() scaling
• Clean canvas restoration when the mouse leaves the canvas or mode is deactivated

Usage

1. Open an image in the editor
2. Press Alt+A to activate magnifying glass mode
3. Move the mouse over the image to see magnified details
4. Press Alt+A again to deactivate the mode

Fixes issue regarding magnifying glass mode implementation.

Original prompt

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This section details on the original issue you should resolve

<issue_title>image Magnifying Glass</issue_title>
<issue_description>Magnifying Glass mode when hold on the image

Alt key + A : Magnifying mode activate

so when put magnifying glass on the image that part is 2x scale up

magnifying box size is 128px x 128px </issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #41

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[volta2030]

LGTM