fix: name the guest in VM/CT health alerts, refresh AI models, propose the recipe's volume choice

- A health problem of a VM or CT names the guest in its title and in the
  Quiet Hours summary; a recovery shows its category by name in the
  reader's language.
- AI model lists reviewed against each provider: Gemini adds 3.6/3.7/3.8
  Flash, Groq adds gpt-oss-120b, and Groq/OpenRouter models no longer
  served are removed.
- OCI installer proposes the volume choice the recipe declares, so a path
  meant for a host directory is proposed as one; Duplicati /source is
  proposed on a host directory.

oci/catalog/apps/duplicati-official.json

@@ -117,7 +117,7 @@
           "managed-volume",
           "host-bind"
         ],
-        "default": "managed-volume",
+        "default": "host-bind",
         "managed_volume": {
           "backup": true,
           "default_size_gb": 8

oci/catalog/apps/duplicati.json

@@ -166,7 +166,7 @@
           "managed-volume",
           "host-bind"
         ],
-        "default": "managed-volume",
+        "default": "host-bind",
         "managed_volume": {
           "backup": true,
           "default_size_gb": 8