pub const APPLIED_DDL_TABLE: &'static str;Expand description
The follower’s DDL idempotency journal: one row per applied ddl entry, keyed by the migration
id (or the entry offset when a source ships none). Unregistered bookkeeping like the offsets
table — never captured/fanned. A crash-window replay (the ddl re-delivered before its cursor
advanced) dedups against this BEFORE re-applying, so an already-applied reshape is skipped exactly
rather than re-run-and-inferred-from-the-error (see ApplyStore::exec_ddl_with_marker).