Lists the custom tables the caller's own company has logged via a Node-RED
log-timeseries flow. These are tables created dynamically in a Postgres
schema named literally after the company's company_id — a different
mechanism from the core platform tables served by /timeseries/{table}.

Only the exact company that created the table can see it. There is no
hierarchy inheritance: a parent company managing child companies does not
see a child's custom tables through this endpoint.