feat(2meet-data-optimizer): route meta orderby including the HivePress sort clause

- 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

tests/live/README.md

@@ -39,7 +39,7 @@ Exit code 0 when every test passed, 1 otherwise. Output per test:
 | `shadow_write` | writes in shadow_read reach native meta (user, term, HivePress listing) |
 | `serialized` | array meta values are stored serialized in flat tables, never "Array" |
 | `resync` | dual_write / shadow_read: flat follows native after every write (4 entities × 2 modes: update, same value, delete, refused writes, stale flat, key rename by meta_id) |
-| `router` | a routed WP_Query returns the same ids, in order, as native (OR, several post types, untyped numeric compares, named orderby, LIKE, keys of two groups, NOT EXISTS with the status/date copy route); routed SQL has no GROUP BY |
+| `router` | a routed WP_Query returns the same ids, in order, as native (OR, several post types, untyped numeric compares, named orderby, LIKE, keys of two groups, NOT EXISTS with the status/date copy route, meta orderby: HivePress sort shape, named clause, meta_key + meta_value_num); routed SQL has no GROUP BY |
 | `zero_side_effect` | zone tables that were never created are never queried on save / delete |
 
 ## Tools (`tools/`)