Add option to automatically reconnect lost database sessions

Problem:
When the database connection is lost, Query Tool shows a confirmation dialog asking whether to establish a new session.

Solution:
It would be useful to have a setting to automatically reconnect without showing this prompt, while keeping the current behavior as the default.

This is particularly useful with serverless PostgreSQL providers like Neon, where connections may be terminated after being idle for some time. Having to manually confirm the reconnect each time interrupts the workflow, especially when returning to an existing Query Tool session.

Start in the Query Tool's existing lost-connection flow, locating the confirmation dialog and how session reconnection is triggered. Trace where Query Tool settings are defined and persisted; done means a setting enables automatic reconnection, the current prompt remains the default, and the behavior works for idle PostgreSQL sessions.