Add config to change the default query row limit

Currently, if no LIMIT if specified, a query will only return 10 results. Add a config to change the default number.

No files, tests, or entry points are named. Start by tracing how queries without an explicit LIMIT receive the current default of 10, then identify the configuration path that controls query defaults. Done means users can configure the default row limit and queries without LIMIT return that configured number while explicit LIMIT values remain unchanged.

Written by the indexing model from the issue text.