fix(2meet-data-optimizer): skip zone deletes on tables that were never created

- TMDO_Zone_Router::delete_post() deleted from wp_wpdo_hot_/cold_{post_type}
  whenever fields were registered for that zone, so every post delete on a
  HivePress site (cold fields registered, module idle, table never created)
  logged a "table doesn't exist" error. Hot and cold deletes now also need
  the table to exist; module state is not checked, so a table left by a
  rolled-back module still loses the rows of deleted posts.
- Live suite zero_side_effect: saving / updating / deleting an hp_listing
  issues no query on missing zone tables (covers PR-054 and this PR).
- Verify: ZoneRouterTest 22 OK; live zero_side_effect + shadow_write +
  serialized 9/9 PASS (old code: zero_side_effect FAIL); unit 687 OK,
  integration 484 OK, phpcs (phpcs.xml) 0, stan OK
- PR: PR-054b

tests/live/README.md

@@ -38,6 +38,7 @@ 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" |
+| `zero_side_effect` | zone tables that were never created are never queried on save / delete |
 
 ## Tools (`tools/`)