fix(models): Add button, probe of managed models, delete list refresh

- ui.js: mount() now wraps non-node children in text nodes (like h()), so
  mount(el, "") no longer throws in appendChild — this is what broke the
  "Add model" form (applyDefaults cleared a status via mount(x,"")).
- probe_model: resolve managed local models too (they are synthesized into the
  registry, not [[models]]) — probing them no longer returns "model not found".
- models.js: await reload() after delete so the row is removed immediately.

web/js/views/models.js

@@ -264,7 +264,7 @@ function row(m, meta, reload) {
               try {
                 await api.deleteModel(m.id);
                 toast(t("toast.deleted"), "good");
-                reload();
+                await reload();
               } catch (e) {
                 toast(String(e.message || e), "bad");
               }