Search for diagram nodes by keyword across all providers and services.
For targeted browsing when you know the provider, use list_providers -> list_services ->
list_nodes instead.
Args:
query: Search term (case-insensitive substring match).
Returns:
List of matching nodes with keys: node, provider, service, import, alias_of (optional).
Sorted by relevance: exact match first, then prefix, then substring.
Connector