feat: add right-click restorer for current site

- Add RightClickRestorer page with active unlock trigger
- Content script with dual-world strategy (isolated + main world)
- Monkey patch preventDefault/stopPropagation via background executeScript
- Overlay penetration for pointer-events blocking layers
- Delegated main-world injection to avoid CSP restrictions
- Async message handling for reliable state updates
- i18n translations (zh/en) and unit tests

i18n/locales/en/features.json

@@ -37,5 +37,9 @@
   "htmlToMarkdown": {
     "title": "HTML to Markdown",
     "description": "Real-time HTML conversion and Markdown preview"
+  },
+  "rightClickRestorer": {
+    "title": "Right Click Restorer",
+    "description": "Detect and restore disabled browser right-click menus"
   }
 }