Implement Mock Test Accounts for Store Review

[bradly0cjw]

Description

Currently, we provide actual user credentials to App Store Connect and Google Play Console reviewers. This poses a security risk and potentially exposes sensitive academic data. We need to implement a dedicated "Mock Account" environment for the review process.

Objectives

• Create a dedicated test user in the backend with the username app_review_test.

• Populate the mock account with sample "iStudy" data (images, videos, and course info) to demonstrate core features.

• Implement a "Demo Mode" toggle in the Flutter app that points to a mock API endpoint if the reviewer's credentials are detected.

Security Justification

Using real credentials violates our internal data privacy policy and risks flagging the account for suspicious login activity (since reviewers may log in from different geographic regions like the US or Ireland).