Give every module that would overflow its login a short slug

An identity is `mesh_<node>_<slug-or-name>` and a backend keeps 20 characters
(an S3 access key). Overflow makes a module unresolvable, and this catalogue
was finding it one module at a time, on a raise: route-proxy on novox is 22,
home-assistant on ace is 23. Two found by hand where a sweep would have found
eighteen.

So the whole catalogue was swept instead, against the longest node name the
mesh actually has (`shanks`, six characters) rather than against the node each
module happens to sit on today — a module is assigned somewhere, and where is
not a property of the manifest. That leaves eight characters for the identity
source, and eighteen modules were over it.

Slugs added, chosen to stay greppable in a provider's user list:

  anthropic-consumer  claude     openai-consumer     openai
  anthropic-manager   anthmgr    portainer           portain
  audit-logger        audit      public-acme         pubacme
  bookshelf           books      qbittorrent         qbt
  cloudflare-dns      cfdns      resolv-conf         resolv
  confluence          confl      resolved-split-dns  splitdns
  home-assistant      hass       route-proxy         rproxy
  invoicing           invoice    verdaccio           verdacc
  mosquitto           mosq
  nextcloud           ncloud

A slug changes the login the mesh mints, so a module already provisioned under
its full name is re-minted under the slug and its old login withdrawn — which
is the provisioner's ordinary business, but it is a change, not a no-op.

Checked with the real parser: every one of the 66 manifests through
`catalogue.ParseManifest`, and every module's `CheckIdentity` against all four
node names. 0 problems, where the same check over the parent commit reports 44.

modules/verdaccio/module.json

@@ -1,6 +1,7 @@
 {
   "module": "verdaccio",
   "version": "1",
+  "slug": "verdacc",
   "capabilities": [
     "container-runtime"
   ],