CaseMark routes document previews back through Mike

Document previews in this fork now load through the main app instead of redirecting the browser to a separate storage URL. In production, that redirect path was breaking - users were seeing "Failed to load document" when trying to view PDFs, Word files, and the like. Keeping the request on the app's own origin fixes the failure and, just as importantly, keeps the app's own permissions in charge of who can see what, rather than handing that decision to the storage layer.

The same change quietly cleaned up a bug in the account settings screen, where a still-loading profile was being shown as if the user had no API key configured. It went out as a hotfix - opened, reviewed, and merged inside a quarter of an hour.