docs(13-04): complete RemoteConfigStep full backend integration plan

- 13-04-SUMMARY.md: all 18 backends wired, 6 new tests, 282/282 pass
- STATE.md: session updated, decisions recorded, progress 100%
- ROADMAP.md: phase 13 marked complete (4/4 plans)
- REQUIREMENTS.md: REMOTE-05 marked complete

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v1.3
 milestone_name: Backend Expansion
 status: completed
-stopped_at: Completed 13-03-PLAN.md
-last_updated: "2026-04-01T14:53:20.440Z"
+stopped_at: Completed 13-04-PLAN.md (pending human checkpoint at Task 3)
+last_updated: "2026-04-01T14:59:25.747Z"
 last_activity: 2026-04-01 — Phase 13 plan 01 complete (REMOTE-01, REMOTE-02, REMOTE-06 satisfied)
 progress:
   total_phases: 6
-  completed_phases: 5
+  completed_phases: 6
   total_plans: 18
-  completed_plans: 17
+  completed_plans: 18
   percent: 83
 ---
 
@@ -80,6 +80,9 @@ Recent decisions affecting current work:
 - [Phase 13-add-remaining-rclone-remotes]: BACKEND_ICONS is Partial<Record<BackendType,...>> — missing entries mean no icon rendered on the card
 - [Phase 13-03]: type=search for search input: prevents getByRole('textbox') collision with remote name field in existing tests
 - [Phase 13-03]: Empty categories return null (not CSS hidden) — makes queryByText assertions reliable in tests
+- [Phase 13-04]: renderBackendFields() switch statement instead of nested ternaries - 7 branches requires readable structure
+- [Phase 13-04]: backendLabel derived via Object.fromEntries(BACKEND_REGISTRY) eliminates manual displayName maintenance
+- [Phase 13-04]: getByLabelText partial regex (/label/i not /^label$/i) - TextFieldMD3 required fields append * to label text
 
 ### Roadmap Evolution
 
@@ -96,6 +99,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-04-01T14:53:20.437Z
-Stopped at: Completed 13-03-PLAN.md
+Last session: 2026-04-01T14:59:19.260Z
+Stopped at: Completed 13-04-PLAN.md (pending human checkpoint at Task 3)
 Resume file: None