fix(2meet-data-optimizer): close the gaps in deferred table upgrades found in the 2.3 review

- a deferred group whose stored definition matches again (reverted, or
  upgraded by another process) goes through end_deferral() instead of staying
  native for good (review F2)
- the tmdo_ensure_group_indexes handler upgrades deferred tables itself: with
  ALTERNATE_WP_CRON the event runs after init in a visitor's request (F3)
- a new group table created while the entity writes to flat stays native
  until the drift fix has filled it from native meta; an opted-in HivePress
  attribute no longer routes searches to an empty table (F6)
- direct_read() returns native values for a deferred group (F10); the Hook
  Bus ignores deferral in aeav_only, as the router does
- dbDelta failures: the definition is recorded only when every column exists
  (schema.upgrade_failed otherwise), so a failed ALTER is retried and the
  group is not released onto missing columns
- test bootstrap: get_metadata() reads the real meta table
- Verify: SchemaUpgradeDeferralTest (6), Hook Bus direct read, integration
  587, unit 703, phpcs, stan
- PR: PR-114 (2.3 acceptance correctness review)

tests/integration/HookBusIntegrationTest.php

@@ -243,6 +243,7 @@ class HookBusIntegrationTest extends TestCase {
 					WPDO_Hook_Bus::sync_from_native( 'user', 4, 'first_name', 'Dora', 'update' );
 
 					$this->assertNull( $this->read_flat_first_name( 4 ) );
+					$this->assertSame( 'Dora', WPDO_Hook_Bus::direct_read( 'user', 4, 'first_name' ), 'direct reads return the native value' );
 				}
 			);
 		} finally {