feat: record live Scaleway backup bucket attributes

Bucket railiance-platform-pg-backup is private in nl-ams with versioning
and a 30-day lifecycle. Fill reef attributes and topology. Create script
is idempotent. Billing budget still needs a console click.

substrate/topology.yaml

@@ -1,21 +1,22 @@
 reef_id: reef-storage
 membership_policy: Add a member when a purchased object-store (bucket/project) is live. Members are provider resources, not hosts.
-members: []
-intended_members:
+members:
   - member_id: platform-audit-storage
     role: primary-backup-object-store
     provider: Scaleway
     product: standard-multi-az
     region: nl-ams
+    bucket: railiance-platform-pg-backup
     resource_id: resource:platform:audit-storage
-    status: planned
+    status: live
     evidence:
       - repo: resource-control
         path: docs/evidence/RESOURCE-WP-0002-primary-selection-2026-08-14.md
+      - path: substrate/object-stores/platform-audit-storage.yaml
+intended_members: []
 access_surfaces:
   - type: s3-https
-    note: Endpoint and bucket are filled after purchase in substrate/object-stores/platform-audit-storage.yaml. No rail.
+    note: Endpoint and bucket live in substrate/object-stores/platform-audit-storage.yaml. No rail.
 unresolved_questions:
-  - Scaleway project/organization id on the paying Railiance (or GmbH) account
-  - Exact bucket name and prefix after create
   - Whether Host Europe Backup Storage or Nextcloud is the T06 second copy
+  - Founder must create a 20 EUR monthly Scaleway budget. This API key cannot write billing_budgets.