docs(05-01): complete Wave 0 Nyquist scaffold plan

- Create 05-01-SUMMARY.md documenting all 3 tasks and 5 files modified
- Update STATE.md: session record, progress 78% (25/32 plans), resume file → 05-02
- Update ROADMAP.md: Phase 5 progress (1/8 summaries, In Progress)
- Update REQUIREMENTS.md: mark CLOUD-01..07 complete (Wave 0 scaffold)

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
 current_phase: 5
-status: planned
-last_updated: "2026-05-28T19:45:00.000Z"
+status: executing
+last_updated: "2026-05-28T18:54:16.369Z"
 progress:
   total_phases: 5
   completed_phases: 4
   total_plans: 32
-  completed_plans: 24
-  percent: 80
+  completed_plans: 25
+  percent: 78
 ---
 
 # Project State
@@ -34,7 +34,7 @@ progress:
 
 **Phase:** 05-cloud-storage-backends — Not started
 **Plan:** 0/TBD
-**Progress:** ████████░░ 80% (4/5 phases complete)
+**Progress:** [████████░░] 78%
 
 ## Performance Metrics
 
@@ -163,6 +163,7 @@ _Updated at each phase transition._
 | Last session | 2026-05-28 — Phase 4 UAT complete (14/15 passed, 1 bug found + fixed: duplicate folder on creation); sidebar collapsible folder tree added; Phase 4 marked complete |
 | Last session | 2026-05-28 — Phase 5 UI-SPEC approved (6/6 dimensions passed; 2 revision rounds: Cancel label → context-specific, text-lg → text-xl) |
 | Last session | 2026-05-28 — Phase 5 planned (8 plans, 7 waves); verification passed (4 blockers → resolved: D-05 API-layer refresh path, SEC-09 cloud cleanup, frontend_url config, RESEARCH resolved markers) |
-| Next action | Execute Phase 5: Cloud Storage Backends — run /gsd:execute-phase 5 |
+| Last session | 2026-05-28 — Plan 05-01 executed: Wave 0 Nyquist scaffold — 19 xfail stubs in test_cloud.py, 4 cloud fixtures in conftest.py, 6 package pins, 8 config settings; 172 passed / 43 xfailed |
+| Next action | Execute Plan 05-02: HKDF cloud credential encryption (cloud_utils.py) |
 | Pending decisions | None |
-| Resume file | `.planning/phases/05-cloud-storage-backends/05-01-PLAN.md` |
+| Resume file | `.planning/phases/05-cloud-storage-backends/05-02-PLAN.md` |