- Sort shape (relation OR of NOT EXISTS + EXISTS on one key, named in orderby): drop it from meta_query, LEFT JOIN the flat table and order by its column, ties by ID
- Named routed clause as the sole orderby, and meta_key + meta_value_num (meta_value on string columns) with IS NOT NULL; stay native when the column would not order like CAST(meta_value AS type), orderby has several keys, or meta_value filters
- Verify: tests/live/run.php router (11/11); fe.sh price__asc / hourly_rate__desc / rating__desc ids == native
- PR: PR-062
