Sending X-Debug: 1 makes the five wholesale list endpoints return a counts-only `debug` block next to the rows: the WHERE that actually ran, how many customers the scope matches before the grid's own filters, how many customers exist per kind/active/archived/step and how many are an expert's trading account. The panel sends the header and console-logs the block when localStorage.debug === '1'. Off by default; DIAG_LOG=false disables it server-side. No names or mobiles. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>