Add support for Firefox data collection permissions

[suveshmoza]

Feature Request

When building extensions for Firefox and submitting them to Add-ons Mozilla, Firefox shows warnings/requires explicit data collection permissions to be declared in the manifest. WXT currently doesn't support configuring browser_specific_settings.gecko.data_collection_permissions, which is a required field for Firefox extensions.

Is your feature request related to a bug?

N/A

What are the alternatives?

As a workaround, developers can manually add the field with a TypeScript ignore comment:

// wxt.config.ts
export default defineConfig({
  manifest: {
    browser_specific_settings: {
      gecko: {
        id: 'extension@xyz',
        // @ts-ignore - WXT doesn't support this field yet
        data_collection_permissions: {
          required: ['none'],
        },
      },
    },
  },
});

However, this workaround:

• Doesn't provide helpful warnings when building for Firefox
• Is not an ideal developer experience

Additional context

Firefox requires this field as documented in their official documentation.

Important Firefox Requirements:

• Firefox built-in consent for data collection and transmission is supported in Firefox for desktop 140 and later, and Firefox for Android 142 and above.
• Beginning November 3rd 2025, all new extensions will be required to adopt the Firefox built-in data collection consent system. Extensions will need to state if and what data they collect or transmit.
• New versions and updates for add-ons that were created before November 3rd don't need to use it at this time, but will have to at some later date.