A previous CSP change suggested by CodeRabbit was not properly
tested and broke inline styling as well as the loading of the
ProConnect image.
Adjust the CSP directives to allow these resources again.
The CSP was missing a default-src directive (flagged by CodeRabbit).
Without it, styles, images, fonts, and media are completely
unrestricted, which undercuts the otherwise strict policy.
Set default-src to 'self' and add an explicit style-src directive
since we rely on inline styles (e.g. #close-msg and the view
toggling use inline style attributes), so style-src needs to allow
'self' and 'unsafe-inline'.