Execute an App tab search

Execute a search on a specific tab of a public App — no authentication required.

Routes tab_id → retriever → results. Each tab can be backed by either:

• An internal retriever (retriever_id) — org-scoped
• A marketplace catalog entry (public_name) — proxied via public API

The inputs dict is passed directly to the retriever's input_schema. Extra top-level fields are automatically merged into inputs.

Example:

{
  "tab_id": "search",
  "inputs": { "query": "red sneakers" },
  "settings": { "limit": 20 }
}