fix: tolerate unknown gateway model types in /api/models

fixes #735: Reranking Models And /api/models

What happened

The upstream AI Gateway /config response included a model entry like:

{
  "id": "cohere/rerank-v3.5",
  "name": "Cohere Rerank 3.5",
  "description": "Rerank 3.5 efficiently finds the most relevant business data to answer a user question...",
  "modelType": "reranking",
  "tags": [],
  "specification": {
    "specificationVersion": "v3",
    "provider": "bedrock",
    "modelId": "cohere/rerank-v3.5",
    "type": "reranking"
  },
  "pricing": {
    "input": "0",
    "output": "0"
  }
}

Why it failed

The current SDK validation for gateway.getAvailableModels() only accepts these modelType values:

• embedding
• image
• language
• video

Because the Gateway payload included modelType: "reranking", the SDK rejected the entire response during validation.

That meant /api/models failed before our code could filter the response down to language models, so the route returned 500.

What this means for reranking models

Reranking models are not supported by this endpoint today.

They should not be returned by /api/models, because this route is used for language-model selection in the app. The correct behavior is:

• ignore unsupported non-language model types such as reranking
• continue returning valid language models
• avoid failing the whole endpoint because of unrelated model categories

Fix summary

We added a fallback path in apps/web/lib/models-with-context.ts so that when Gateway metadata validation fails, the app:

• inspects the raw error response
• extracts valid language model entries
• ignores unsupported entries like reranking models
• continues serving /api/models successfully

Result

After the fix:

• reranking models are skipped
• language models still load normally
• /api/models returns 200 instead of 500