4 plans across 3 waves to expand from 7 to 17 rclone backends: - Plan 01 (W1): Registry refactoring, BackendType derivation, 10 new entries - Plan 02 (W2): OAuthInstructions, GdriveAuthToggle, BackendIcons components - Plan 03 (W2): BackendSelectionStep UX overhaul with categories, search, icons - Plan 04 (W3): RemoteConfigStep wiring for all new backends + visual verify Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>