Extension: Single privacy toggle

**O3 KR1**
Enable MetaMask services opt-in rate of at least [90%] by implementing a single privacy toggle.

**Context**
The MetaMask Services Privacy Toggle will allow users to opt in/out of all first party API services. Through this, we can increase the user’s awareness of data transfer and storage, and provide a consentful way to fully utilize all MetaMask’s API backed services. We’ve maintained a Metametrics opt-in rate of at least 90% in the last 12 months – we should use this as a benchmark for the single privacy toggle.

- This privacy toggle will allow users to opt in/out of all first party API services. Further, this will allow MetaMask to better explain why certain features like “Portfolio”, “Buy”, “Bridge”, and “Swap” buttons are enabled.
- The implementation will provide an option for new users to opt into this preference during onboarding, and for existing users to opt in within settings.
- Before we begin development, we will determine:
- Design explorations based on Privacy Toggle design brief
- Validate designs through concept and usability testing
- Finalize implementation plan according to testing results
- While not a KR metric, we want to measure the effectiveness of privacy awareness and consent with the overall FLI rate. We can track the privacy opt-in rate vs FLI incident ratio and see how our privacy awareness efforts have an impact on fund loss incidents.

The issue does not identify implementation files or tests; begin with the Privacy Toggle design brief and the onboarding and settings entry points described here. Define and validate the design before implementation, then confirm that one preference controls first-party API opt-in/out for new-user onboarding and existing-user settings.

Written by the indexing model from the issue text.