staging-main: PRs merged without review

[nikolay-panovski]

This issue tracks code across Pull Requests merged into a "de-facto-main" branch without the guarantees for code stability and testing from the actual main branch.

Participating code

• Qr code #27
• Multiple Screens quest (frontend app side) #31
• Language game #32
• Image upload #33
• Upgade account #34

[nikolay-panovski]

All code originally put into STAGING-main has been merged via Pull Requests (still without full-on testing). This issue will remain as a tracker of potential last-moment PRs that also do not get tested.