fix(settings): replacing a managed local model no longer breaks save

- put_settings now heals [routing] after the managed-servers list changes: a
  removed server whose port is taken over by a new one is treated as a
  replacement (old id → new id in default + every tier); truly vanished ids are
  stripped; an emptied default falls back to the first managed server / pool
  model. Previously the stale id failed validation and the save errored.
- /admin/api/cmf/port now returns managed:true when the port is held by this
  gateway's own managed server; the Settings port check shows that as info
  ("freed on restart, replacing is fine") instead of a red "port busy".

web/js/i18n/en.js

@@ -267,6 +267,7 @@ export default {
   "settings.cmf.checkPort": "Check port",
   "settings.cmf.portFree": "port is free",
   "settings.cmf.portBusy": "port is in use",
+  "settings.cmf.portOwn": "in use by this gateway's current server — freed on restart, replacing is fine",
   "settings.cmf.useSuggested": "use {port}",
   "settings.cmf.serving": "serving {model} on :{port}",
   "settings.cmf.intro": "Run models locally with the cortiq engine — works even offline or when the router is down.",