Added the ability to specify a local endpoint.

- Old Q&A answers now properly clear when asking new questions
- Supporting emails display with full details (subject, author, date, folder)
- Email click handlers work correctly (no more "NaN" errors)
- URLs in AI answers are now clickable links
- Complete database deletion using indexedDB.deleteDatabase()
- Fixed all "can't access property 'style'" errors
- Added verification to confirm empty database
- Better error handling throughout
- Now indexes Inbox subfolders