Introducing PlanetScale Insights: Advanced query monitoring

Introduces PlanetScale Insights, an in-dashboard query statistics tool with an interactive time-based graph for monitoring rows read, rows written, query latency, and queries per second. Adds a section showing all queries run in the last 24 hours with metrics like run count, total time, time per query, rows returned, rows read, and rows affected. Enables drilling down into individual queries to see slow instances and generate EXPLAIN plans. Demonstrates a practical use case of identifying a slow query linked to a schema change and confirming performance improvements.