docs(05-06): complete cloud upload/test integration plan — SUMMARY and STATE

- Create 05-06-SUMMARY.md: documents.py cloud extension + 20 passing cloud tests
- Update STATE.md: plan 5→6 of 8, session notes, next action → 05-07
- Update ROADMAP.md: mark 05-06 as complete [x]

.planning/STATE.md

@@ -4,13 +4,13 @@ milestone: v1.0
 milestone_name: milestone
 current_phase: 5
 status: executing
-last_updated: "2026-05-29T09:21:57.000Z"
+last_updated: "2026-05-29T05:51:25.000Z"
 progress:
   total_phases: 5
   completed_phases: 4
   total_plans: 32
-  completed_plans: 28
-  percent: 87
+  completed_plans: 31
+  percent: 90
 ---
 
 # Project State
@@ -28,13 +28,13 @@ progress:
 | 2 | Users & Authentication | ✓ Complete (5/5 plans) |
 | 3 | Document Migration & Multi-User Isolation | ✓ Complete (5/5 plans, UAT passed, security gate passed) |
 | 4 | Folders, Sharing, Quotas & Document UX | ✓ Complete (9/9 plans, UAT 14/15 passed, 1 bug fixed) |
-| 5 | Cloud Storage Backends | In Progress (5/8 plans complete) |
+| 5 | Cloud Storage Backends | In Progress (6/8 plans complete) |
 
 ## Current Position
 
 **Phase:** 05-cloud-storage-backends — In Progress
-**Plan:** 5/8
-**Progress:** [████████░░] 87%
+**Plan:** 6/8
+**Progress:** [█████████░] 90%
 
 ## Performance Metrics
 
@@ -182,6 +182,7 @@ _Updated at each phase transition._
 | Last session | 2026-05-28 — Plan 05-03 executed: GoogleDriveBackend (Drive v3, cache_discovery=False, asyncio.to_thread) + OneDriveBackend (MSAL, resumable upload, CHUNK_SIZE=10MB); 262 passed / 43 xfailed / 1 pre-existing failure |
 | Last session | 2026-05-28 — Plan 05-04 executed: WebDAVBackend + NextcloudBackend (SSRF double-guard, asyncio.to_thread, list_folder); 262 passed / 43 xfailed / 1 pre-existing failure |
 | Last session | 2026-05-29 — Plan 05-05 executed: cloud.py (7 endpoints), main.py (routers registered), admin.py (SEC-09 cloud cleanup); 262 passed / 43 xfailed / 1 pre-existing failure |
-| Next action | Execute Plan 05-06: Cloud Document Upload/Download |
+| Last session | 2026-05-29 — Plan 05-06 executed: documents.py cloud upload+content-proxy extension; all 15 xfail stubs promoted to 20 passing tests (CLOUD-03, CLOUD-05, CLOUD-07); 282 passed / 24 xfailed / 1 pre-existing failure |
+| Next action | Execute Plan 05-07: Cloud Frontend Integration |
 | Pending decisions | None |
-| Resume file | `.planning/phases/05-cloud-storage-backends/05-06-PLAN.md` |
+| Resume file | `.planning/phases/05-cloud-storage-backends/05-07-PLAN.md` |