Google One Tap Sign-In Fixes

Resolved multiple issues with Google One Tap sign-in and improved the usage dashboard.

Improvements

The usage page now shows your current balance prominently and removes misleading hover effects from non-interactive elements.

Fixed several issues causing Google One Tap sign-in to fail, including session handling errors and redirect loops.

Fixed an issue where signing in with a different OAuth provider than originally used would show a confusing error instead of a helpful redirect.

Plus 21 internal changes for stability and performance.