Modify Model Picker Label

Nucleic-Session: 3854DB9E-8136-4DF7-95E7-BBFC7E615174
Co-authored-by: Nucleic <[email protected]>

NucleicRemote/NucleicRemote/Views/Theme.swift

@@ -453,7 +453,13 @@ struct ModelMenu: View {
         }
         return catalog.groups
     }
-    private var label: String { model.map { catalog.displayName($0) } ?? "Default model" }
+    // `nil` model means "host default": name that model (the catalog's fallback SKU) rather than
+    // showing a generic "Default model". Falls back to the generic text only for the empty catalog.
+    private var label: String {
+        if let model { return catalog.displayName(model) }
+        let defaultName = catalog.displayName(catalog.fallbackModel)
+        return defaultName.isEmpty ? "Default model" : defaultName
+    }
 
     var body: some View {
         Menu {