Adds forgot/reset password, signup email verification, sign-out-of-all-devices,
note-usage and certificate display in account settings, and password-changed
security emails. Fixes study sessions being lost on server restart by
persisting them to disk, and fixes sanitizeStudyUsers silently dropping the
new pending-token fields on load. Also surfaces the lesson discussion board
in the main site nav, trims the sign-in page for returning users, and renames
colossiansStudy.tsx/colossiansStudyData.ts to studyPages.tsx/legacyColossiansData.ts
now that the study system covers more than Colossians.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>