seed: planned Scaleway backup store for WP-0002

Identity, topology, consumer bindings, and the planned attribute file
(region nl-ams, endpoint/bucket still null). Post-purchase fill is
REEF-STORAGE-WP-0002.

bindings/consumers.yaml

@@ -0,0 +1,13 @@
+reef_id: reef-storage
+consumers_potential:
+  - consumer_id: rapp-postgres
+    resource_id: resource:platform:audit-storage
+    purpose: WAL archive and physical base backups for platform-pg
+    readiness_state: declared
+    evidence:
+      - repo: resource-control
+        path: workplans/RESOURCE-WP-0002-procure-postgres-backup-storage.md
+consumers_actual: []
+notes:
+  - Actual consumer is recorded only after WAL flows (RESOURCE-WP-0002-T05).
+  - rapp-postgres consumes a reviewed destination; it does not procure the bucket.