feat: use new staging vss auth services

[ovitrif]

Description

This PR uses the new staging services to enable secured backups using vss-server with JWT authentication enabled by the new lnurl-auth-server backend service for issuing JWT tokens based on the contract expected by ldk-node and vss-rust-client.

QA Notes

Tests

• Test with new wallet (do not expect old wallets to work):
  • crate wallet > fund > transfer to spending
  • send onchain once
  • send lightning once
  • remove all suggestion cards but one
  • remove all widgets
  • settings > backup or restore > save seed > reset and restore wallet
  • use seed to restore
  • expect wallet to restore correctly:
    • expect ldk-node restore success: channel + activity history correct
    • expect settings restore success: suggestion cards + widgets removed