docs(06-new-backends): create phase plan

4 plans across 3 waves: Wave 0 TDD stubs, Wave 1 data layer (parallel: OneDrive/GCS/B2 + SFTP/SftpAuthToggle), Wave 2 RemoteConfigStep wiring.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -57,7 +57,13 @@ Plans:
   3. User can select Google Cloud Storage as a backend, fill in the required fields, and generate a valid rclone.conf containing `[type = google cloud storage]`
   4. User can select Backblaze B2 as a backend, enter their application key credentials, and generate a valid rclone.conf containing `[type = b2]`
   5. All four new backends appear in the BackendSelectionStep list and each produces a downloadable config+scripts bundle
-**Plans**: TBD
+**Plans**: 4 plans
+
+Plans:
+- [ ] 06-00-PLAN.md — Wave 0 TDD stubs: failing tests for all four new backends across registry, rclone-conf, and RemoteConfigStep
+- [ ] 06-01-PLAN.md — Registry + schema + RCLONE_TYPE_MAP for OneDrive, GCS, Backblaze B2
+- [ ] 06-02-PLAN.md — Registry + schema + RCLONE_TYPE_MAP for SFTP + SftpAuthToggle component
+- [ ] 06-03-PLAN.md — Wire all four backends into RemoteConfigStep + human verification
 
 ### Phase 7: Validation & UX Polish
 **Goal**: Users receive immediate inline feedback when they enter incorrectly formatted values, and can access plain-language explanations on confusing credential fields without leaving the wizard
@@ -79,5 +85,5 @@ Plans:
 | 3. Wizard UI | v1.0 | 5/5 | Complete | 2026-03-27 |
 | 4. Review, Download & Security | v1.0 | 5/5 | Complete | 2026-03-27 |
 | 5. Tech Debt | 4/4 | Complete   | 2026-03-30 | - |
-| 6. New Backends | v1.1 | 0/TBD | Not started | - |
+| 6. New Backends | v1.1 | 0/4 | Not started | - |
 | 7. Validation & UX Polish | v1.1 | 0/TBD | Not started | - |