Get top-level Partle platform statistics.
Use for size questions ("how big is Partle?", "how many stores does
Partle cover?"). Aggregate counts only — no per-product or per-store
data; use `search_products` / `search_stores` for that.
Read-only. No authentication. Cheap, but rarely changes — long-running
agents should cache the result.
Returns:
``{"total_products": int, "total_stores": int, "description": str}``.
Connector