Enters drain mode: stops accepting new episodes but lets active ones finish. Schedule timers are cancelled. Event triggers are ignored.

Initializes actor state from a config map and raw expectations list.

Used by DynamicActor to start actors from DB-defined configurations without requiring a compiled actor module.

raw_expectations can be {id, opts_keyword_list} tuples (same as from the DSL) or %Expectation{} structs.