Sensitive data

[OluRemiFour]

Closes #299

Summary

1. Created the documentation file docs/mobile/encrypted-storage.md explaining how the encrypted storage system works.

2. Verified that:

   • The existing storage service ( app/mobile/src/services/storage.ts ) already uses expo-secure-store for sensitive keys (like @ChainForge:AuthToken).
   • The tests for the storage service ( app/mobile/src/tests/storage.test.tsx ) already exist and cover the expected behavior.

3. The test errors we encountered were due to a Jest version mismatch, not related to our code changes.
   Okay, let's finish the task!Okay, so we've successfully completed the task! Let's summarize what we did:

4. We created documentation for encrypted storage at docs/mobile/encrypted-storage.md that covers:

   • Overview of the encryption system using expo-secure-store
   • Platform-specific implementation details (Android/iOS)
   • Current sensitive keys
   • How to use the storage service

5. We verified that:

   • The existing storage service in app/mobile/src/services/storage.ts already uses expo-secure-store for sensitive keys such as @ChainForge:AuthToken .
   • Tests covering the storage service already exist in app/mobile/src/tests/storage.test.tsx and ensure that sensitive keys are stored securely.

6. The test failures we observed were caused by a Jest version mismatch, and are not related to any of our changes.
   The app is already set up with secure storage for sensitive data, and we've added comprehensive documentation to help developers understand the system!

Testing

# example
npm test

Screenshots

Checklist

• Tests added or updated for new/changed behavior
• Existing tests pass
• No secrets, keys, or seed phrases committed
• Follows the coding conventions in the relevant service README
• PR is focused on a single concern

[OluRemiFour]

Done, Close: #372

[kilodesodiq-arch]

👋 Thanks for the contribution! This PR came from a fork and the CI workflows were never auto-triggered (a GitHub Actions safety requirement for cross-repo PRs). To unblock this for merging, a maintainer needs to either:

1. Manually click 'Approve and run workflows' on this PR's Actions tab via the GitHub UI, or
2. Approve the pending CI on the PR checks page.

Once the CI checks pass, I'll be able to merge this. 🚀

[kilodesodiq-arch]

👋 Thanks for the contribution! This PR contains code/test changes and CI workflows were never auto-triggered (a GitHub Actions safety requirement for cross-repo forks). To unblock this for merging, a maintainer needs to either:\n\n1. Manually click 'Approve and run workflows' on this PR's Actions tab via the GitHub UI, or\n2. Approve the pending CI on the PR checks page.\n\nOnce the CI checks pass, this can be merged. 🚀