Manage API keys from the dashboard

[phucnguyen1707]

Summary

• add an API keys dashboard tab backed by the existing account key API
• let users create, copy a one-time token, list, and revoke keys without exposing stored secrets
• normalize SQLite timestamps as UTC and show load failures separately from an empty key list

Tests

• bun test tests/ (201 passed)
• npx tsc --noEmit
• npm run build