fix: playground model id alignment across org boundaries

Two QA-reported bugs on the "Open in Playground" path. Both come
down to the model id the playground submits not matching what
``/v1/models`` / the dispatcher key off:

* Routes page (OSS UI) emitted ``default/<name>`` for routes in the
  platform Org and 404'd. ``use-open-playground`` keyed off the
  ``is_platform`` flag alone; stale caches that drop the flag
  slipped through. Also accept the well-known ``name === 'default'``
  (``PLATFORM_PRINCIPAL_NAME`` on the backend) as a fallback signal.

* My Models page (enterprise UI, non-admin) emitted bare ``<name>``
  with no Org prefix for non-platform routes. Use ``model.name``
  from ``/v2/my-models`` verbatim — the backend ("fix: principal
  prefix in my-models") now rewrites that field to the OpenAI-style
  id server-side, which also closes the cross-Org grant gap a
  client-side cache lookup can't (the granting Org isn't in the
  caller's member list). Card title now shows the prefixed id, so
  users can tell apart same-named models from different Orgs.

Routes page keeps ``useOpenPlayground`` — that surface is always
scoped to the caller's own Org, the local cache is sufficient, and
``/model-routes`` still returns the raw ``name``.

Also drops the now-unused ``onClick`` prop on ``ModelItem``: the
card had ``clickable={false}`` so the parent-passed handler was
already dead code; the Button drives the playground navigation.

src/pages/llmodels/components/model-item.tsx

@@ -119,13 +119,16 @@ const renderTag = (item: any, index = 0) => {
 
 const ModelItem: React.FC<{
   model: Record<string, any>;
-  onClick: (model: any) => void;
 }> = (props) => {
-  const { model, onClick } = props;
+  const { model } = props;
   const intl = useIntl();
   const navigate = useNavigate();
 
-  const handleOpenPlayGround = () => {
+  // ``model.name`` from ``/v2/my-models`` is the OpenAI-style id
+  // (org-prefixed for non-platform routes, bare for platform). Use it
+  // verbatim — the playground / dispatcher both key off that exact id.
+  const handleOpenPlayGroundClick = () => {
+    const modelName = encodeURIComponent(model.name);
     for (const [category, path] of Object.entries(categoryToPathMap)) {
       if (
         model.categories?.includes(category) &&
@@ -134,15 +137,15 @@ const ModelItem: React.FC<{
           modelCategoriesMap.speech_to_text
         ].includes(category)
       ) {
-        navigate(`${path}&model=${model.name}`);
+        navigate(`${path}&model=${modelName}`);
         return;
       }
       if (model.categories?.includes(category)) {
-        navigate(`${path}?model=${model.name}`);
+        navigate(`${path}?model=${modelName}`);
         return;
       }
     }
-    navigate(`/playground/chat?model=${model.name}`);
+    navigate(`/playground/chat?model=${modelName}`);
   };
 
   // context length
@@ -167,7 +170,6 @@ const ModelItem: React.FC<{
     <CardWrapper>
       <TemplateCard
         height={140}
-        onClick={() => onClick(model)}
         clickable={false}
         hoverable={true}
         ghost
@@ -237,7 +239,7 @@ const ModelItem: React.FC<{
                   size="middle"
                   className="btn"
                   type="primary"
-                  onClick={handleOpenPlayGround}
+                  onClick={handleOpenPlayGroundClick}
                 >
                   {intl.formatMessage({ id: 'models.openinplayground' })}
                 </Button>