Make Web consistent with EX crypto UX

[pmaier1]

Input gathering

Web side

• Remove ability to choose your own Recovery passphrase
• Key reset during sign-in
• Settings (related: Replace the "Encryption" settings with a new settings tab element-web#26468)
  • Key storage (previously 'secure backup' or 'chat backup' in EX)
  • Move footguns to developer mode
• Update terminology to match MSC4161
• Invisible crypto
  • Force device verification during sign-in
  • TOFU
  • Exclude non-cross-signed devices
• Design consistency between EX and Web

[BillCarsonFr]

Next Steps:

• Proper gap analysis between EX / WebR

[mxandreas]

For the sake of clarity, I am closing this ticket as we're tracking these problems as part of the internal roadmap ticket ER-69.