Add Cloud Map seeder discovery with VPC Lattice operator templates.

Agents poll AETHERFORGE_CLOUD_MAP_ENDPOINT to sync know_node gossip; deploy plans attach route_via DNS hints for standalone operator registries.

server/web/public/spread/cloud-map/service-registry.json

@@ -0,0 +1,17 @@
+{
+  "Name": "aetherforge-seeder",
+  "NamespaceId": "REPLACE_CLOUD_MAP_NAMESPACE_ID",
+  "Description": "AetherForge erasure seeder instances for VPC Lattice discovery",
+  "DnsConfig": {
+    "DnsRecords": [
+      {
+        "Type": "A",
+        "TTL": 10
+      }
+    ],
+    "RoutingPolicy": "MULTIVALUE"
+  },
+  "HealthCheckCustomConfig": {
+    "FailureThreshold": 1
+  }
+}