2.20.4

Fix an embedded MySQL/InnoDB REPEATABLE READ deadlock between continueAsNew() and signal admission for an unrelated workflow instance.

The correction preserves caller-owned transaction read views and avoids replaying user workflow code to recover from a deadlock. It also preserves pending default and named signal handoffs across continuation.

The published package passed the installed MySQL regression and scope checks. Affected applications retain their own upgrade verification tracked in #1043.

Contributor: @Loosand.