Button styles across site

- Update Profile
- Every button on the page

- Sign Up / Login / Manage Account Connections
- Both connector buttons
- Sign Up / Login buttons
- Reset My Password button
- Change Password button

- News pages
- Update/Submit buttons
- The Choose File button in light mode does not look like a button at all
- Approval button
- Delete button

These should not have Boost mustard backgrounds in their default state.

They should all be using the same casing for the text. Some buttons are ALL UPPERCASE, some are not. None of them should be all uppercase.

They all need hover states in both light and dark mode.

Review the Update Profile, Sign Up, Login, Manage Account Connections, and News pages named in the issue, starting with their existing button styles. Check buttons in both light and dark modes, including Choose File, and compare their default, hover, and text casing. Done means the listed buttons share non-mustard defaults, consistent casing, and hover states in both modes.

Written by the indexing model from the issue text.