Cascade.FactorSourceCascade-aware rule factoring.
Per-optimization memo for flat rule runs. A cache is scoped to one finalizer/context pair; do not share it across independent optimizer calls.
val run :
?cache:cache ->
ctx:Ctx.t ->
finalize:(Stylesheet.rule -> Stylesheet.rule) ->
Stylesheet.rule list ->
Stylesheet.rule listRun the DAG-backed factor fixpoint.