cost_per_query is missing

[nipunn1313]

It looks like this PR removed it
#576

Judging from PR description - I would guess this was by accident.

It is linked from https://medium.com/dbsql-sme-engineering/introducing-granular-cost-monitoring-for-databricks-sql-e7ea4e77daf5 - so seems like it's breaking links.

[mittalpk]

This was already fixed by #614 (merged 2026-01-12), which restored both dbsql/cost_per_query/PrPr/DBSQL Cost Dashboard (PrPr).lvdash.json and dbsql/cost_per_query/PrPr/DBSQL Cost Per Query MV (PrPr).sql exactly as they were before #576 accidentally removed them. Confirmed present on main with the dbsql_cost_per_query materialized view intact. Should be safe to close.