Device: name, public_key (hex), added_at. FieldHistoryView: field_id, field_name, current_value, entries[]. Messages: list_devices, add_device, revoke_device, list_trashed, restore_item, purge_item, purge_all_trash, get_field_history. Also adds stub cases in popup-only.ts switch to keep tsc happy until Tasks 3-5 wire up the real handlers. Co-Authored-By: Claude <noreply@anthropic.com>