NATS10: the bus module serves no restore point tool and keeps no state kept

Reverts bbd9f638, c2e017a4 and b6884796; cmd/mesh-nats-snapshot/restore.go is as before them. The manifest test
asserts the claim serves only the reading verbs and the keeper's state is asked, requests, spent.

Builds: design 47 G §554, §555

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

modules/nats/module.json

@@ -32,9 +32,7 @@
         "list",
         "show",
         "check",
-        "orphans",
-        "snapshot-kept",
-        "restore-kept"
+        "orphans"
       ]
     }
   ],
@@ -100,10 +98,6 @@
       "history": 1,
       "ttl-seconds": 86400,
       "read-only": true
-    },
-    {
-      "name": "kept",
-      "history": 1
     }
   ],
   "listens": [
@@ -263,8 +257,7 @@
         "state": [
           "asked",
           "requests",
-          "spent",
-          "kept"
+          "spent"
         ],
         "asks": true,
         "keeps": true,