Declare credential form none for the provision, which hands consumers no credential

The manifest judge refuses an offer that says no credential form (issue 1585).

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

modules/route-proxy/module.json

@@ -9,6 +9,9 @@
     {
       "name": "route",
       "scope": "mesh",
+      "credential": {
+        "form": "none"
+      },
       "identity": false,
       "answered-by": "helper"
     }