shortcuts and config menu (#4530)

# Description of Changes

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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: Claude <[email protected]>

frontend/public/locales/en-GB/translation.json

@@ -255,6 +255,22 @@
     "cacheInputs": {
       "name": "Save form inputs",
       "help": "Enable to store previously used inputs for future runs"
+    },
+    "hotkeys": {
+      "title": "Keyboard Shortcuts",
+      "description": "Hover a tool to see its shortcut or customise it below. Click \"Change shortcut\" and press a new key combination. Press Esc to cancel.",
+      "errorModifier": {
+        "mac": "Include ⌘ (Command), ⌥ (Option), or another modifier in your shortcut.",
+        "windows": "Include Ctrl, Alt, or another modifier in your shortcut."
+      },
+      "errorConflict": "Shortcut already used by {{tool}}.",
+      "none": "Not assigned",
+      "customBadge": "Custom",
+      "defaultLabel": "Default: {{shortcut}}",
+      "capturing": "Press keys… (Esc to cancel)",
+      "change": "Change shortcut",
+      "reset": "Reset",
+      "shortcut": "Shortcut"
     }
   },
   "changeCreds": {