Examine source code of yafce — Yet Another Claude Extension

{
  "manifest_version": 3,
  "name": "yafce — Yet Another Claude Extension",
  "short_name": "yafce",
  "version": "1.0.5",
  "description": "Adds an in-page theme toggle and usage indicator to claude.ai.",
  "browser_specific_settings": {
    "gecko": {
      "id": "yafce@joedmin.cz",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "https://claude.ai/*",
    "https://*.claude.ai/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://claude.ai/*",
        "https://*.claude.ai/*"
      ],
      "js": [
        "src/hook.js"
      ],
      "run_at": "document_start",
      "world": "MAIN"
    },
    {
      "matches": [
        "https://claude.ai/*",
        "https://*.claude.ai/*"
      ],
      "js": [
        "src/bridge.js",
        "src/theme.js",
        "src/usage.js"
      ],
      "css": [
        "src/ui.css"
      ],
      "run_at": "document_idle"
    }
  ]
}